Nanofiber Hydrogel Research Articles

Spermidine Crosslinked Gellan Gum-Based "Hydrogel Nanofibers" as Potential Tool for the Treatment of Nervous Tissue Injuries: A Formulation Study.

PurposeAim of the work was to develop a potential neural scaffold, endowed with neuroprotective and neuroregenerative potential, to be applied at the site of nervous tissue injuries: nanofibers, consisting of gellan gum (GG), spermidine (SP) and gelatin (GL), were prepared via electrospinning. SP was selected for its neuroprotective activity and cationic nature that makes it an ideal GG cross-linking agent. GL was added to improve the scaffold bioactivity.MethodsMixtures, containing 1.5% w/w GG and increasing SP concentrations (0–0.125% w/w), were prepared to investigate GG/SP interaction and, thus, to find the best mixture to be electrospun. Mixture rheological and mechanical properties were assessed. The addition of 0.1% w/w GL was also investigated. The most promising GG/SP/GL mixtures were added with poly(ethylene oxide) (PEO) and poloxamer (P407) and, then, electrospun. The resulting fibers were characterized in terms of size and mechanical properties and fiber morphology was observed after soaking in water for 24 hours. Nanofiber biocompatibility was assessed on Schwann cells.ResultsMore and more structured GG/SP mixtures were obtained by increasing SP concentration, proving its cross-linking potential. After blending with PEO and P407, the mixture consisting of 1.5% w/w GG, 0.05% w/w SP and 0.1% w/w GL was electrospun. The resulting nanofibers appeared homogenous and characterized by a plastic behavior, suggesting a good mechanical resistance when applied at the injury site. Nanofibers were insoluble in aqueous media and able to form a thin gel layer after hydration. GG/SP/GL nanofibers showed a higher compatibility with Schwann cells than GG/SP ones.ConclusionSP and GL allowed the production of homogenous GG-based nanofibers, which preserved their structure after contact with aqueous media and showed a good compatibility with a neural cell line. After local application at the injury site, nanofibers should support and guide axonal outgrowth, releasing SP in a controlled manner.

Integrin receptor-binding nanofibrous peptide hydrogel for combined mesenchymal stem cell therapy and nitric oxide delivery in renal ischemia/reperfusion injury

BackgroundMesenchymal-based therapy has been utilized as a practical approach in the treatment of renal ischemia/reperfusion (I/R) injury. However, low cell retention and survival in the ischemic site have remained challenging issues. To bridge this gap, the integrin receptor-binding RGD peptide-functionalized, s-nitroso-n-acetyl penicillamine (SNAP)-loaded hydrogel was used to transplant Wharton's jelly-mesenchymal stem cells (WJ-MSCs).MethodsApart from physicochemical and rheological characterizations that confirmed entangled interlocking β-sheets with nanofibrous morphology, real-time RT-PCR, ROS production, serum biomarker concentrations, and histopathological alterations were explored in a mouse model to assess the therapeutic efficacy of formulations in the treatment of renal I/R injury.ResultsThe RGD-functionalized Fmoc-diphenylalanine (Fmoc-FF + Fmoc-RGD) hydrogel supported the spread and proliferation of WJ-MSCs in vivo. Notably, intralesional injection of nitric oxide donor combined with the embedded WJ-MSCs caused superior recovery of renal I/R injury compared to free WJ-MSCs alone in terms of histopathological scores and renal function indices. Compared to the I/R control group, oxidative stress and inducible nitric oxide synthase (iNOS) expression biomarkers showed a significant decline, whereas endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) expression exhibited a significant increment, indicating regeneration of the injured endothelial tissue.ConclusionThe findings confirmed that the hydrogels containing WJ-MSCs and nitric oxide donors can promote the regeneration of renal I/R injuries by increasing angiogenic factors and cell engraftment.

An Electroconductive, Thermosensitive, and Injectable Chitosan/Pluronic/Gold-Decorated Cellulose Nanofiber Hydrogel as an Efficient Carrier for Regeneration of Cardiac Tissue.

Myocardial infarction is a major cause of death worldwide and remains a social and healthcare burden. Injectable hydrogels with the ability to locally deliver drugs or cells to the damaged area can revolutionize the treatment of heart diseases. Herein, we formulate a thermo-responsive and injectable hydrogel based on conjugated chitosan/poloxamers for cardiac repair. To tailor the mechanical properties and electrical signal transmission, gold nanoparticles (AuNPs) with an average diameter of 50 nm were physically bonded to oxidized bacterial nanocellulose fibers (OBC) and added to the thermosensitive hydrogel at the ratio of 1% w/v. The prepared hydrogels have a porous structure with open pore channels in the range of 50–200 µm. Shear rate sweep measurements demonstrate a reversible phase transition from sol to gel with increasing temperature and a gelation time of 5 min. The hydrogels show a shear-thinning behavior with a shear modulus ranging from 1 to 12 kPa dependent on gold concentration. Electrical conductivity studies reveal that the conductance of the polymer matrix is 6 × 10−2 S/m at 75 mM Au. In vitro cytocompatibility assays by H9C2 cells show high biocompatibility (cell viability of >90% after 72 h incubation) with good cell adhesion. In conclusion, the developed nanocomposite hydrogel has great potential for use as an injectable biomaterial for cardiac tissue regeneration.

Injectable PEG-induced silk nanofiber hydrogel for vancomycin delivery

Silk fibroin nanofiber hydrogels mimicking the extracellular matrix structure have gained increased attention in the field of tissue engineering. In this study, an amorphous silk fibroin nanofiber solution was prepared using a new dissolving technique. The keys to the dissolving method include the preparation of nanofibrous silk film by dissolving silk in a CaCl2-Formic Acid (Ca-FA) solution with subsequent dissolution in a CaCl2-Ethanol-H2O ternary solution at room temperature. The resulting solution was primarily composed of native silk nano/microfibers, which primarily form amorphous structures. The amorphous silk fibroin nanofiber solution was further processed into an injectable hydrogel through a simple physical blend with polyethylene glycol (PEG). The nanofiber structure and PEG accelerated silk gelation, and the fastest gelation time was 150 s at concentrations of 5% silk and 85% PEG. The morphology, secondary structure, and rheological properties of injectable silk fibroin nanofiber hydrogels were subsequently characterized. Silk gelation was accompanied by a structural transition from random coil to β-sheet, and the resulting injectable hydrogel had an irregular lamellar structure. The antibiotic vancomycin (VANCO) was loaded in the injectable hydrogel, and the release of VANCO from the injectable hydrogel was assessed at pH values of 4.5 and 7.4. The VANCO-loaded injectable silk fibroin nanofiber hydrogel exhibited superior antibacterial properties against bacteria. A cytotoxicity test preliminarily demonstrated that the VANCO-loaded injectable silk fibroin nanofiber hydrogel had good biocompatibility for applications in tissue engineering.

Vitamin C supramolecular hydrogel for enhanced cancer immunotherapy

Vitamin C (VitC) has shown great promise to promote cancer immunotherapy, however, its high hydrophilicity makes it quickly excreted, leading to limited therapeutic efficiency even with frequent high-dose administration. Herein, we provide a pioneering report about the employment of VitC amphiphile self-assembled nanofiber hydrogels for enhanced cancer immunotherapy. Specifically, driven by hydrogen bonding and hydrophobic interactions, the synthesized VitC amphiphile, consisting of a hydrophilic VitC headgroup and a hydrophobic alkyl chain, could self-assemble into an injectable nanofiber hydrogel with self-healing properties. The formed VitC hydrogel not only serves as a reservoir for VitC but also acts as an effective delivery platform for stimulator of interferon genes (STING) agonist-4 (SA). Interestingly, the VitC hydrogel itself exhibits antitumor effects by upregulating genes related to interferon (IFN) signaling, apoptotic signaling and viral recognition and defense. Moreover, the SA-encapsulated VitC hydrogel (SA@VitC hydrogel) synergistically activated the immune system to inhibit the progression of both local and abscopal tumors.

Application of adipose mesenchymal stem cell-derived exosomes-loaded β-chitin nanofiber hydrogel for wound healing

Clarifying the role and mechanism of exosome gel in wound repair can provide a new effective strategy for wound treatment. The cellular responses of adipose mesenchymal stem cell-derived exosomes (AMSC-exos) and the wound healing ability of AMSC-exos-loaded β-chitin nanofiber (β-ChNF) hydrogel were studied in vitro in mouse fibroblasts cells (L929) and in vivo in rat skin injury model. The transcriptome and proteome of rat skin were studied with the use of sequenator and LC-MS/MS, respectively. 80 and 160 μg/mL AMSC-exos could promote the proliferation and migration of mouse fibroblastic cells. Furthermore, AMSC-exos-loaded β-ChNF hydrogel resulted in a significant acceleration rate of wound closure, notably, acceleration of re-epithelialization, and increased collagen expression based on the rat full-thickness skin injury model. The transcriptomics and proteomics studies revealed the changes of the expression of 18 genes, 516 transcripts and 250 proteins. The metabolic pathways, tight junction, NF-κB signaling pathways were enriched in Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway. Complement factor D (CFD) and downstream Aldolase A (Aldoa) and Actn2 proteins in rats treated with AMSC-exos-loaded β-ChNF hydrogel were noticed and further confirmed by ELISA and Western blot. These findings suggested that AMSC-exos-loaded β-ChNF hydrogel could promote wound healing with the mechanism which is related to the effect of AMSC-exos on CFD and downstream proteins.

Fabrication of Gelatin Nanofibers by Electrospinning-Mixture of Gelatin and Polyvinyl Alcohol.

Gelatin, one of the most abundant, naturally derived biomacromolecules from collagen, is widely applicable in food additives, cosmetic ingredients, drug formulation, and wound dressing based on their non-toxicity and biodegradability. In parallel, polyvinyl alcohol (PVA), a synthetic polymer, has been commonly applied as a thickening agent for coating processes in aqueous systems and a major component in healthcare products for cartilage replacements, eye lubrication, and contact lenses. In this study, a new type of mixed hydrogel nanofiber was fabricated from gelatin and polyvinyl alcohol by electrospinning under a feasible range of polymer compositions. To determine the optimal composition of gelatin and polyvinyl alcohol in nanofiber fabrication, several key physicochemical properties of mixed polymer solutions such as viscosity, surface tension, pH, and electrical conductance were thoroughly characterized by a viscometer, surface tensiometer, water analyzer, and carbon electron probe. Moreover, the molecular structures of polymeric chains within mixed hydrogel nanofibers were investigated with Fourier-transform infrared spectroscopy. The morphologies and surface elemental compositions of the mixed hydrogel nanofibers were examined by the scanning electron microscope and energy-dispersive X-ray spectroscopy, respectively. The measurement of water contact angles was performed for measuring the hydrophilicity of nanofiber surfaces. Most importantly, the potential cytotoxicity of the electrospun nanofibers was evaluated by the in vitro culture of 3T3 fibroblasts. Through our extensive study, it was found that a PVA-rich solution (a volumetric ratio of gelatin/polyvinyl alcohol <1) would be superior for the efficient production of mixed hydrogel nanofibers by electrospinning techniques. This result is due to the appropriate balance between the higher viscosity (~420–~4300 10−2 poise) and slightly lower surface tension (~35.12–~32.68 mN/m2) of the mixed polymer solution. The regression on the viscosity data also found a good fit by the Lederer–Rougier’s model for a binary mixture. For the hydrophilicity of nanofibers, the numerical analysis estimates that the value of interfacial energy for the water contact on nanofibers is around ~−0.028 to ~−0.059 J/m2.

On the mechanism for the highly sensitive response of cellulose nanofiber hydrogels to the presence of ionic solutes

Hydrogels formed by cellulose nanofibers (CNFs) find use in a variety of applications. CNF hydrogels generally stiffen and ultimately flocculate with increasing salt concentrations. While charge repulsion explains the behavior of nanocellulose variants that have been stabilized by charged groups, it has been a puzzle why ions have such a pronounced effect also on CNFs with unmodified surfaces. We studied the effect of ionic solutes on native CNF hydrogels, and found that already at very low concentrations of around 1 mM, ions cause crowding of the hydrogels. The ionic solutes used were NaCl, Na2SO4, NaI, NaSCN, and sodium acetate. For the hydrogels, we used low densities of CNFs which lead to relatively weak gels that were highly sensitive to salts. Screening of the electrical double layer could not explain the results at such low ion concentrations. To understand cellulose-ion interactions, we used computational molecular dynamics simulations. The results provide an explanation by the effect of ions on the structure of the hydration layers of the cellulose. Understanding how and why ions affect the properties of native CNF hydrogels can help in for example manufacture of CNFs and when using CNFs as material components, substrates for enzymes, or as rheology modifiers. Ion-effects on the hydration layer of cellulose may also be important for more fundamental understanding of interfacial interactions of cellulose with water under different conditions.Graphical abstract

Regulation of gut microbiome with redox responsible bacterial cellulose hydrogel for precision chemo-radiotherapy of intestinal cancer

Although various types of radiosensitive nanoplatforms are explored to enhance radiotherapy, digestible and radiosensitive nanofiber hydrogel with sensitive responsiveness to the intestinal environment, greatly amplified radiation-induced intestinal tumor destruction, as well as the ability to regulate gut microbiome is still demanded. Herein, sulfhydryl crosslinked bacterial cellulose hydrogel (SulBC gel) was synthesized through silylation and oxidation reaction. Anticancer drug, cis-dichlorodiamineplatinum (CDDP) is loaded into the hydrogel (CDDP@SulBC gel) for precision radiotherapy of intestinal cancer. The CDDP@SulBC gel selectively degrades and consequently exhibits an accelerated drug release behavior in reductive environments. Meanwhile, the CDDP@SulBC gel can increase X-ray-induced double-strand breaks, induce G2/M phase arrest, and enhance the radio-sensitivity to intestinal tumor cells. Upon intragastric administration of CDDP@SulBC gel, the hydrogel is noninvasively monitored in the gastrointestine by micro-CT imaging contributed to the relative high Z-element of silicon and shows an excellent anti-tumor efficacy under X-ray-irradiation of the human intestinal cancer xenograft nude mice. Additionally, the hydrogel can also elevate the ratio of Bacteroidetes / Firmicutes and reconstruct gut microbiome balance, benefiting to the reduction of colitis induced by irradiation. This work thus presents a digestible nanofiber hydrogel-based radiosensitizer with in vivo micro-CT imaging, intestine-specific decomposition/drug release profiles, and great efficacy in chemo-radiotherapy of cancer.

Fabrication and characterization of gas-assisted core-shell hydrogel nanofibers as a drug release system with antibacterial activity

In this research, fabrication and characterization of core-shell hydrogel nanofibrous mats containing Polylactic acid/Sage extract in the core and Polyvinylpyrrolidone/Polyvinyl alcohol in the shell, utilizing a novel gas-assisted coaxial electrospinning technique was investigated. The use of an extra gas blowing system allowed to increase core and shell flow rates remarkably and contributed to the higher production of nanofibers in a very short time. To construct the core-shell structure, first, the core solution containing Polylactic acid 8 wt% and Sage extract 10 wt% was prepared. Then the shell solution including Polyvinylpyrrolidone 20 wt% and Polyvinyl alcohol 9 wt% was made and citric acid 2.5 wt% was added as the crosslinking agent. The core and shell solutions were loaded separately in a coaxial spinneret and the gas-assisted coaxial electrospinning was conducted. In the end, the electrospun mats were cured in an oven to obtain core-shell hydrogel nanofibers. The kinetics of the swelling, the release of Sage extract, and the effects of various amounts of crosslinker on the swelling and release process were investigated for core-shell hydrogel nanofibers and then compared to that of the single-core and shell systems. Moreover, the antibacterial assay was performed on the fabricated core-shell hydrogel nanofibers to assess the antimicrobial properties of the electrospun mats. Further evaluations were performed through SEM, TEM, FTIR, DSC, and TGA analyses to determine the morphology and structure of individual systems. The electrospun mats can find excessive applications in biomedical fields as antibacterial dressings for superficial wounds.

Engineered Tough Silk Hydrogels through Assembling β-Sheet Rich Nanofibers Based on a Solvent Replacement Strategy.

β-Sheet rich silk nanofiber hydrogels are suitable scaffolds in tissue regeneration and carriers for various drugs. However, unsatisfactory mechanical performance limits its applications. Here, insight into the silk nanofibers stimulates the remodeling of previous solvent systems to actively regulate the assembly of silk nanofibers. Formic acid, a solvent of regenerated silk fibroin, is used to shield the charge repulsion of silk nanofibers to facilitate the nanofiber assembly under concentrated solutions. Formic acid was replaced with water to solidify the assembly, which induced the formation of a tough hydrogel. The hydrogels generated with this process possessed a modulus of 5.88 ± 0.82 MPa, ultimate stress of 1.55 ± 0.06 MPa, and toughness of 0.85 ± 0.03 MJ m-3, superior to those of previous silk hydrogels prepared through complex cross-linking processes. Benefiting from the dense gel network and high β-sheet content, these silk nanofiber hydrogels had good stability and antiswelling ability. The modulus could be modulated via changing the silk nanofiber concentration to provide differentiation signals to stem cells. Improved mechanical and bioactive properties with these hydrogels suggest utility in biomedical and engineering fields. More importantly, our present study reveals that the in-depth understanding of silk nanofibers could infuse power into traditional fabrication systems to achieve more high performance biomaterials, which is seldom considered in silk material studies.

Engineering cryoelectrospun elastin-alginate scaffolds to serve as stromal extracellular matrices

Scaffold-based regenerative strategies that emulate physical, biochemical, and mechanical properties of the native extracellular matrix (ECM) of the region of interest can influence cell growth and function. Existing ECM-mimicking scaffolds, including nanofiber (NF) mats, sponges, hydrogels, and NF-hydrogel composites are unable to simultaneously mimic typical composition, topography, pore size, porosity, and viscoelastic properties of healthy soft-tissue ECM. In this work, we used cryoelectrospinning to fabricate 3D porous scaffolds with minimal fibrous backbone, pore size and mechanical properties similar to soft-tissue connective tissue ECM. We used salivary glands as our soft tissue model and found the decellularized adult salivary gland (DSG) matrix to have a fibrous backbone, 10–30 μm pores, 120 Pa indentation modulus, and ∼200 s relaxation half time. We used elastin and alginate as natural, compliant biomaterials and water as the solvent for cryoelectrospinning scaffolds to mimic the structure and viscoelasticity of the connective tissue ECM of the DSG. Process parameters were optimized to produce scaffolds with desirable topography and compliance similar to DSG, with a high yield of >100 scaffolds/run. Using water as solvent, rather than organic solvents, was critical to generate biocompatible scaffolds with desirable topography; further, it permitted a green chemistry fabrication process. Here, we demonstrate that cryoelectrospun scaffolds (CESs) support penetration of NIH 3T3 fibroblasts 250–450 µm into the scaffold, cell survival, and maintenance of a stromal cell phenotype. Thus, we demonstrate that elastin-alginate CESs mimic many structural and functional properties of ECM and have potential for future use in regenerative medicine applications.

MP38-06 SONIC HEDGEHOG SIGNALING IN CORPORA CAVERNOSAL CELLS FROM PROSTATECTOMY, DIABETIC, HYPERTENSION AND PEYRONIE’S PATIENTS WITH ERECTILE DYSFUNCTION

You have accessJournal of UrologyCME1 May 2022MP38-06 SONIC HEDGEHOG SIGNALING IN CORPORA CAVERNOSAL CELLS FROM PROSTATECTOMY, DIABETIC, HYPERTENSION AND PEYRONIE’S PATIENTS WITH ERECTILE DYSFUNCTION Sarah Martin, Timothy Searl, Samuel Ohlander, Kevin McVary, and Carol Podlasek Sarah MartinSarah Martin More articles by this author , Timothy SearlTimothy Searl More articles by this author , Samuel OhlanderSamuel Ohlander More articles by this author , Kevin McVaryKevin McVary More articles by this author , and Carol PodlasekCarol Podlasek More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002592.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Erectile dysfunction (ED) treatments are minimally effective in prostatectomy and diabetic patients due to injury to the cavernous nerve. With denervation the critical smooth muscle undergoes apoptosis and the penis becomes fibrotic, thus altering corpora cavernosal architecture. In order to devise novel ED therapies, prevention of corpora cavernosal remodeling is critical. Sonic hedgehog (SHH) treatment by peptide amphiphile (PA) nanofiber hydrogel, suppresses smooth muscle apoptosis and improves erectile function in a rat CN injury ED model. We examine if human corpora cavernosal smooth muscle responds in a similar manner to SHH treatment.In this study we: 1.) Examine if human corpora cavernosal smooth muscle cells from primary culture of ED patient tissues, respond to Sonic hedgehog (SHH) treatment by increasing growth rate, as in our in vivo animal model. 2.) Determine if human corpora cavernosal cells from patients with differing underlying mechanisms of ED development (prostatectomy, diabetes, hypertension, cardiovascular disease), respond similarly to SHH treatment. 3.) Identify if organ culture conditions (glucose) affect growth of corpora cavernosal smooth muscle and the response to SHH signaling. 4.) Examine the vascular component of ED (hypertension and cardiovascular disease). METHODS: Human corpora cavernosal tissue was obtained from prostatectomy, diabetic, hypertension, cardiovascular disease and Peyronie’s (control) patients (n=40) that were under going prosthesis implant to treat ED. Primary cultures (n=17) were established, and corpora cavernosal cells from passage 3-4 were treated with SHH protein, MSA (control), 5E1 SHH inhibitor, and PBS (control). Growth was quantified by counting the number of cells using a hemocytometer at 3-4 days. The concentration of SHH protein for maximal growth was examined, in addition to a lipid modified more active SHH peptide. RESULTS: SHH treatment increased smooth muscle growth in human corpora cavernosal cells from prostatectomy, diabetic, and Peyronie’s patients in a similar manner (43-53%). SHH inhibition decreased smooth muscle growth (24-32%). There was no difference in growth using 25ug and 10ug SHH peptide. A more active (150X) SHH peptide further enhanced growth (20%). SHH protein increased growth more in diabetic smooth muscle under high glucose conditions. SHH inhibition was less effective under high glucose conditions. SHH treatment increased growth less in cells from hypertension and cardiovascular disease patients. CONCLUSIONS: Corpora cavernosa smooth muscle from prostatectomy, diabetic, and Peyronie’s patients increased in response to SHH treatment in a similar manner, suggesting that SHH treatment would be beneficial to enhance smooth muscle regeneration in patients with ED of multiple origins. There is a threshold concentration of SHH protein above which smooth muscle growth is enhanced. Lipid modified SHH engendered a more robust growth response. High glucose conditions that may be present in under controlled diabetic patients would not detract from SHH usefulness as a protectant for corpora cavernosal morphology. Understanding how human corpora cavernosal tissue responds to SHH treatment is critical for clinical translation to ED patients. Source of Funding: NIH/NIDDK DK101536 © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e620 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Sarah Martin More articles by this author Timothy Searl More articles by this author Samuel Ohlander More articles by this author Kevin McVary More articles by this author Carol Podlasek More articles by this author Expand All Advertisement PDF DownloadLoading ...

Sonic hedgehog signaling in corpora cavernosal cells from prostatectomy, diabetic, hypertension and Peyronie's patients with erectile dysfunction

ABSTRACT Introduction Erectile dysfunction (ED) treatments are minimally effective in prostatectomy and diabetic patients due to injury to the cavernous nerve. With denervation the critical smooth muscle undergoes apoptosis and the penis becomes fibrotic, thus altering corpora cavernosal architecture. In order to devise novel ED therapies, prevention of corpora cavernosal remodeling is critical. Sonic hedgehog (SHH) treatment by peptide amphiphile (PA) nanofiber hydrogel, suppresses smooth muscle apoptosis and improves erectile function in a rat CN injury ED model. We examine if human corpora cavernosal smooth muscle responds in a similar manner to SHH treatment. Objective In this study we: 1.) Examine if human corpora cavernosal smooth muscle cells from primary culture of ED patient tissues, respond to Sonic hedgehog (SHH) treatment by increasing growth rate, as in our in vivo animal model. 2.) Determine if human corpora cavernosal cells from patients with differing underlying mechanisms of ED development (prostatectomy, diabetes, hypertension, cardiovascular disease), respond similarly to SHH treatment. 3.) Identify if organ culture conditions (glucose) affect growth of corpora cavernosal smooth muscle and the response to SHH signaling. 4.) Examine the vascular component of ED (hypertension and cardiovascular disease). Methods Human corpora cavernosal tissue was obtained from prostatectomy, diabetic, hypertension, cardiovascular disease and Peyronie's (control) patients (n=40) that were under going prosthesis implant to treat ED. Primary cultures (n=17) were established, and corpora cavernosal cells from passage 3-4 were treated with SHH protein, MSA (control), 5E1 SHH inhibitor, and PBS (control). Growth was quantified by counting the number of cells using a hemocytometer at 3-4 days. The concentration of SHH protein for maximal growth was examined, in addition to a lipid modified more active SHH peptide. Results SHH treatment increased smooth muscle growth in human corpora cavernosal cells from prostatectomy, diabetic, and Peyronie's patients in a similar manner (43-53%). SHH inhibition decreased smooth muscle growth (24-32%). There was no difference in growth using 25ug and 10ug SHH peptide. A more active (150X) SHH peptide further enhanced growth (20%). SHH protein increased growth more in diabetic smooth muscle under high glucose conditions. SHH inhibition was less effective under high glucose conditions. SHH treatment increased growth less in cells from hypertension and cardiovascular disease patients. Conclusion Corpora cavernosa smooth muscle from prostatectomy, diabetic, and Peyronie's patients increased in response to SHH treatment in a similar manner, suggesting that SHH treatment would be beneficial to enhance smooth muscle regeneration in patients with ED of multiple origins. There is a threshold concentration of SHH protein above which smooth muscle growth is enhanced. Lipid modified SHH engendered a more robust growth response. High glucose conditions that may be present in under controlled diabetic patients would not detract from SHH usefulness as a protectant for corpora cavernosal morphology. Understanding how human corpora cavernosal tissue responds to SHH treatment is critical for clinical translation to ED patients. Disclosure Work supported by industry: no.

Mechanical Force Induced Self-Assembly of Chinese Herbal Hydrogel with Synergistic Effects of Antibacterial Activity and Immune Regulation for Wound Healing.

Skin wounds, especially infected chronic wounds, have attracted worldwide attention due to the high prevalence and poor treatment outcomes. Hydrogel dressings with antibacterial ability and immune regulation property are urgently required. Herein, inspired by the grinding treatment of traditional Chinese medicine, mechanical force is introduced to promote the effective molecular collision and accelerate the self-assembly of chitosan (CS) and puerarin (PUE) for fabricating Chinese-herb-based hydrogels. The antibacterial rate of CS@PUE (C@P) hydrogel is more than 95%, and the wound closed rate is twice that of the control group. Interestingly, the rational design of C@P hydrogels with different PUE ratios enables a refined control over hydrogel formation, nanofiber appearance, viscoelastic, physicochemical, and biological properties. The extraordinary antibacterial ability of C@P hydrogels may originate from the nanofiber structure and the improved zeta potential on account of the orientation of amino groups in CS . Thus, the synergistically antibacterial and immune regulation properties of C@P hydrogels kill bacteria and relieve inflammation in the wound bed, ensuring the anti-infection effect, and boosting wound healing. In addition to providing a universal mechanosynthesis of PUE-based hydrogel for wound healing, this finding is expected to increase the attention paid to Chinese herbal medicines in the construction of biomaterials.

Sonic Hedgehog Signaling in Corpora Cavernosal Cells from Prostatectomy, Diabetic, Hypertension and Peyronie's Patients with Erectile Dysfunction

ABSTRACT Introduction Erectile dysfunction (ED) treatments are minimally effective in prostatectomy and diabetic patients due to injury to the cavernous nerve. With denervation the critical smooth muscle undergoes apoptosis and the penis becomes fibrotic, thus altering corpora cavernosal architecture. In order to devise novel ED therapies, prevention of corpora cavernosal remodeling is critical. Sonic hedgehog (SHH) treatment by peptide amphiphile (PA) nanofiber hydrogel, suppresses smooth muscle apoptosis and improves erectile function in a rat CN injury ED model. We examine if human corpora cavernosal smooth muscle responds in a similar manner to SHH treatment. Objective In this study we: 1.) Examine if human corpora cavernosal smooth muscle cells from primary culture of ED patient tissues, respond to Sonic hedgehog (SHH) treatment by increasing growth rate, as in our in vivo animal model. 2.) Determine if human corpora cavernosal cells from patients with differing underlying mechanisms of ED development (prostatectomy, diabetes, hypertension, cardiovascular disease), respond similarly to SHH treatment. 3.) Identify if organ culture conditions (glucose) affect growth of corpora cavernosal smooth muscle and the response to SHH signaling. 4.) Examine the vascular component of ED (hypertension and cardiovascular disease). Methods Human corpora cavernosal tissue was obtained from prostatectomy, diabetic, hypertension, cardiovascular disease and Peyronie's (control) patients (n=40) that were under going prosthesis implant to treat ED. Primary cultures (n=17) were established, and corpora cavernosal cells from passage 3-4 were treated with SHH protein, MSA (control), 5E1 SHH inhibitor, and PBS (control). Growth was quantified by counting the number of cells using a hemocytometer at 3-4 days. The concentration of SHH protein for maximal growth was examined, in addition to a lipid modified more active SHH peptide. Results SHH treatment increased smooth muscle growth in human corpora cavernosal cells from prostatectomy, diabetic, and Peyronie's patients in a similar manner (43-53%). SHH inhibition decreased smooth muscle growth (24-32%). There was no difference in growth using 25ug and 10ug SHH peptide. A more active (150X) SHH peptide further enhanced growth (20%). SHH protein increased growth more in diabetic smooth muscle under high glucose conditions. SHH inhibition was less effective under high glucose conditions. SHH treatment increased growth less in cells from hypertension and cardiovascular disease patients. Conclusions Corpora cavernosa smooth muscle from prostatectomy, diabetic, and Peyronie's patients increased in response to SHH treatment in a similar manner, suggesting that SHH treatment would be beneficial to enhance smooth muscle regeneration in patients with ED of multiple origins. There is a threshold concentration of SHH protein above which smooth muscle growth is enhanced. Lipid modified SHH engendered a more robust growth response. High glucose conditions that may be present in under controlled diabetic patients would not detract from SHH usefulness as a protectant for corpora cavernosal morphology. Understanding how human corpora cavernosal tissue responds to SHH treatment is critical for clinical translation to ED patients. Disclosure No

Cell-based dressings: A journey through chronic wound management

The field of regenerative medicine has undergone a paradigm shift in recent decades thanks to the emergence of novel therapies based on the use of living organisms. The development of cell-based strategies has become a trend for the treatment of different conditions and pathologies. In this sense, the need for more adequate, biomimetic and well-planned treatments for chronic wounds has found different and innovative strategies, based on the combination of cells with dressings, which seek to revolutionize the wound healing management. Therefore, the objective of this review is to analyze the current state and the latest advances in the research of cell-based dressings for chronic wounds, ranging from traditional and "second generation" bioengineered living skin equivalents to mesenchymal stem cell dressings; the latter include biopolymeric porous scaffolds, electrospun nanofiber meshes, hydrogels and 3D printed bio-printed dressings. Finally, this review updates the completed and ongoing clinical trials in this field and encourages researchers to rethink these new approaches, manufacturing processes and mechanisms of action, as well as their administration strategies and timings.

Stem cell-homing hydrogel-based miR-29b-5p delivery promotes cartilage regeneration by suppressing senescence in an osteoarthritis rat model.

Osteoarthritis (OA) is a common joint disease characterized by progressive loss of cartilage and reduction in lubricating synovial fluid, which lacks effective treatments currently. Here, we propose a hydrogel-based miRNA delivery strategy to rejuvenate impaired cartilage by creating a regenerative microenvironment to mitigate chondrocyte senescence that mainly contributes to cartilage breakdown during OA development. An aging-related miRNA, miR-29b-5p, was first found to be markedly down-regulated in OA cartilage, and their up-regulation suppressed the expression of matrix metalloproteinases and senescence-associated genes (P16INK4a/P21) via ten-eleven-translocation enzyme 1 (TET1). An injectable bioactive self-assembling peptide nanofiber hydrogel was applied to deliver agomir-29b-5p, which was functionalized by conjugating a stem cell–homing peptide SKPPGTSS for endogenous synovial stem cell recruitment simultaneously. Sustained miR-29b-5p delivery and recruitment of synovial stem cells and their subsequent differentiation into chondrocytes led to successful cartilage repair and chondrocyte rejuvenation. This strategy enables miRNA-based therapeutic modality to become a viable alternative for surgery in OA treatment.

Using UV-Responsive Nanoparticles to Provide In Situ Control of Growth Factor Delivery and a More Constant Release Profile from a Hydrogel Environment.

Nanoparticles are popular delivery vehicles, but their diffusional release results in inconstant drug delivery. Here, we flatten the delivery profile into a more constant, zero-order profile. Brain-derived neurotrophic factor (BDNF) is attached to photoactive titanium dioxide nanoparticles and loaded into a nanofibrous self-assembling peptide (SAP) hydrogel. Different UV exposure conditions show three distinct profiles, including a counterintuitive decrease in release after UV exposure. We propose that the adsorption of the freed growth factor onto the hydrogel nanofibers affects release. Nanoparticles diffuse from the hydrogel readily, carrying the bound growth factor, but the freed growth factor (released from the nanoparticles by UV) instead interacts with─and is released less readily from─the hydrogel. UV shifts growth factor from nanoparticles to the hydrogel, therefore changing the diffusional release. Through midpoint UV exposure, we achieve a flattened delivery profile─unusual for diffusion─by changing in situ the amount of growth factor bound to the diffusing nanoparticles. With nanoparticle diffusion alone, we observed an increasing release profile with 36% of release in the first 6 h and 64% in the second 6 h. With midway UV exposure, this was controlled to 49 and 51%, respectively. The release of an unbound (soluble) control growth factor, glial cell-line derived neurotrophic factor (GDNF), was not affected by UV treatment, demonstrating the potential for independent control of temporal delivery profiles in a multiagent material.

Highly Adhesive, Stretchable and Breathable Gelatin Methacryloyl-based Nanofibrous Hydrogels for Wound Dressings.

Adhesive and stretchable nanofibrous hydrogels have attracted extensive attraction in wound dressings, especially for joint wound treatment. However, adhesive hydrogels tend to display poor stretchable behavior. It is still a significant challenge to integrate excellent adhesiveness and stretchability in a nanofibrous hydrogel. Herein, a highly adhesive, stretchable, and breathable nanofibrous hydrogel was developed via an in situ hybrid cross-linking strategy of electrospun nanofibers comprising dopamine (DA) and gelatin methacryloyl (GelMA). Benefiting from the balance of cohesion and adhesion based on photocross-linking of methacryloyl (MA) groups in GelMA and the chemical/physical reaction between GelMA and DA, the nanofibrous hydrogels exhibited tunable adhesive and mechanical properties through varying MA substitution degrees of GelMA. The optimized GelMA60-DA exhibited 2.0 times larger tensile strength (2.4 MPa) with an elongation of about 200%, 2.3 times greater adhesive strength (9.1 kPa) on porcine skin, and 3.1 times higher water vapor transmission rate (10.9 kg m-2 d-1) compared with gelatin nanofibrous hydrogels. In parallel, the GelMA60-DA nanofibrous hydrogels could facilitate cell growth and accelerate wound healing. This work presented a type of breathable nanofibrous hydrogels with excellent adhesive and stretchable capacities, showing great promise as wound dressings.