Human Fibroblast Growth Research Articles

N-Acetyl Cysteine-Mediated Improvements in Dental Restorative Material Biocompatibility.

The fibroblast-rich gingival tissue is usually in contact with or adjacent to cytotoxic polymer-based dental restoration materials. The objective of this study was to determine whether the antioxidant amino acid, N-acetyl cysteine (NAC), reduces the toxicity of dental restorative materials. Human oral fibroblasts were cultured with bis-acrylic, flowable composite, bulk-fill composite, self-curing acrylic, and titanium alloy test specimens. Cellular behavior and function were analyzed on and around the materials. Impregnation of the bulk-fill composite and self-curing acrylic with NAC reduced their toxicity, improving the attachment, growth, and function of human oral fibroblasts on and around the materials. These mitigating effects were NAC dose dependent. However, NAC impregnation of the bis-acrylic and flowable composite was ineffective, with no cells attaching to nor around the materials. Although supplementing the culture medium with NAC also effectively improved fibroblast behaviors, direct impregnation of materials with NAC was more effective than supplementing the cultures. NAC-mediated improvements in fibroblast behavior were associated with reduced production of reactive oxygen species and oxidized glutathione together with increased glutathione reserves, indicating that NAC effectively directly scavenged ROS from materials and reinforced the cellular antioxidant defense system. These results establish a proof of concept of NAC-mediated improvements in biocompatibility in the selected dental restorative materials.

Silver nanoparticles modified hFGF2-linking camelina oil bodies accelerate infected wound healing

Bacterial infection wounds are common in life. At present, although various wound materials have shown antibacterial activity, there is a lack of overall strategy to promote wound healing. Therefore, it is necessary to develop multifunctional wound materials. In this study, silver nanoparticles (Ag NPs) modified camelina oil bodies (OB) which surface covalently bonded human fibroblast growth factor 2 (Ag NPs-hFGF2-OB) were designed for the treatment of bacterial infection wounds. The prepared Ag NPs-hFGF2-OB not only act as an antibacterial agent to realize sterilization, but also act as a tissue repair agent that effectively promotes wound healing. Ag+ was reduced in situ to Ag NPs by ascorbic acid, and the activity of hFGF2 protein was not affected after hFGF2-OB was modified by Ag NPs, which displaying broad apectrum antibacterial ability for both S. aureus and E. coli, with an antibacterial rate of more than 70 % (the concentration of Ag NPs was 20 μg/mL, the hFGF2 protein concentration was 20 µg/mL). Ag NPs-hFGF2-OB can effectively promote the migration of NIH/3T3 cells, showing good biocompatibility. The mouse bacterial infection wound model experiments proved that the wound healing rate of Ag NPs-hFGF2-OB group (the concentration of Ag NPs was 20 μg/mL, the hFGF2 protein concentration was 20 µg/mL) was much higher than other treatment groups, especially on the 7th day after treatment, the wound healing rate reached 71.71 ± 2.38 %, while the healing rate of other treatment groups were only 34.54 ± 1.10 %, 37.08 ± 2.85 % and 47.99 ± 2.01 %. Therefore, Ag NPs-hFGF2-OB, which can inhibit bacterial growth, promotes collagen deposition, granulation tissue regeneration and angiogenesis without any significant toxicity, shows good potential for application in the repair of bacterial infection wounds.

Combining a Density Gradient of Biomacromolecular Nanoparticles with Biological Effectors in an Electrospun Fiber-Based Nerve Guidance Conduit to Promote Peripheral Nerve Repair.

Peripheral nerve injury is a serious medical problem with limited surgical and clinical treatment options. It is of great significance to integrate multiple guidance cues in one platform of nerve guidance conduits (NGCs) to promote axonal elongation and functional recovery. Here, a multi-functional NGC is constructed to promote nerve regeneration by combining ordered topological structure, density gradient of biomacromolecular nanoparticles, and controlled delivery of biological effectors to provide the topographical, haptotactic, and biological cues, respectively. On the surface of aligned polycaprolactone nanofibers, a density gradient of bioactive nanoparticles capable of delivering recombinant human acidic fibroblast growth factor is deposited. On the graded scaffold, the proliferation of Schwann cells is promoted, and the directional extension of neurites from both PC12 cells and dorsal root ganglions is improved in the direction of increasing particle density. After being implanted in vivo for 6 and 12 weeks to repair a 10-mm rat sciatic nerve defect, the NGC promotes axonal elongation and remyelination, achieving the regeneration of the nerve not only in anatomical structure but also in functional recovery. Taken together, the NGC provides a favorable microenvironment for peripheral nerve regeneration and holds great promise for realizing nerve repair with an efficacy close to autograft.

Benefits of Circulating Human Metabolites from Fish Cartilage Hydrolysate on Primary Human Dermal Fibroblasts, an Ex Vivo Clinical Investigation for Skin Health Applications

Due to its significant exposure to stressful environmental factors, the skin undergoes a high remodeling rate over time, which alters not only its appearance but also its functionality. This alteration of the skin, namely photoaging, is characterized by dryness and a loss of elasticity that mainly originates from the dysregulation of dermal fibroblast activities. In order to overcome such tissue outcome, cosmetic products have evolved toward nutricosmetics, thus promoting beauty from within. Among bio-actives of interest, bio-peptides deriving from plant or animal sources may exert various biological activities beyond their nutritional value. However, studies remain mostly descriptive and the mode of action at the cellular level in clinic remains a concern. In a recent clinical trial, it was showed that supplementation with a fish cartilage hydrolysate (FCH) improved signs of chronological and photoaging-induced skin changes in healthy women. Here, using an original ex vivo clinical approach adapted to nutricosmetic purpose, we further demonstrated that this fish cartilage hydrolysate was absorbed and that the circulating metabolites produced in humans following FCH intake stimulate human dermal fibroblast growth, promote specific hyaluronan production, up-regulate elastin synthesis and inhibit MMP-1 and 3 expression along with the enhancement of TGF-β release. Altogether, these data provide clues on the mechanisms likely contributing to the beneficial impact of FCH on human skin functionality by supporting hydration, elasticity and limiting the expression of catabolic factors involved in photoaging onset.

Juvenile toxicity study of PF-07256472/recifercept, a recombinant human soluble fibroblast growth factor receptor 3, in 2-3-month-old cynomolgus monkeys.

Achondroplasia is an autosomal disorder caused by point mutation in the gene encoding fibroblast growth factor receptor 3 (FGFR3) and resulting in gain of function. Recifercept is a potential disease modifying treatment for achondroplasia and functions as a decoy protein that competes for ligands of the mutated FGFR3. Recifercept is intended to restore normal bone growth by preventing the mutated FGFR3 from negative inhibitory signaling in pediatric patients with achondroplasia. Here we evaluated the potential effects of twice weekly administration of recifercept to juvenile cynomolgus monkeys (approximately 3-months of age at the initiation of dosing) for 6-months. No adverse effects were noted in this study, identifying the high dose as the no-observed-adverse-effect-level and supporting the use of recifercept in pediatric patients from birth. Considering that juvenile toxicity studies in nonhuman primates are not frequently conducted, and when they are conducted they typically utilize animals ≥9months of age, this study demonstrates the feasibility of executing a juvenile toxicity study in very young monkeys prior to weaning.

Exogenous pyruvate and recombinant human basic fibroblast growth factor maintain pluripotency and enhance global metabolic activity of bovine embryonic stem cells grown on low-density feeder layers

A suitable microenvironment or niche is essential for self-renewal and pluripotency of stem cells cultured in vitro, including bovine embryonic stem cells (bESCs). Feeder cells participate in the construction of stem cell niche by secreting growth factors and extracellular matrix proteins. In this study, metabolomics and transcriptomics analyses were used to investigate the effects of low-density feeder cells on bESCs. The results showed that bESCs co-cultured with low-density feeder cells experienced a decrease in pluripotent gene expression, cell differentiation, and a reduction of central carbon metabolic activity. When cell-permeable pyruvate (Pyr) and recombinant human basic fibroblast growth factor (rhbFGF) were added to the culture system, the pluripotency of bESCs on low-density feeder layers was rescued, and acetyl-coenzyme A (AcCoA) synthesis and fatty acid de novo synthesis increased. In addition, rhbFGF enhances the effects of Pyr and activates the overall metabolic level of bESCs grown on low-density feeder layers. This study explored the rescue effects of exogenous Pyr and rhbFGF on bESCs cultured on low-density feeder layers, which will provide a reference for improvement of the PSC culture system through the supplementation of energy metabolites and growth factors.

Application of recombinant human basic fibroblast growth factor in repair of the aged dog bite wound

BackgroundDog bite wounds usually have severe local soft tissue damage and the wounds are likely to be contaminated by a large number of bacteria or even a series of rare pathogenic bacteria, leading to repeated infection and delayed wound healing. Recombinant human basic fibroblast growth factor (rh-bFGF) has excellent ability to promote wound repair and widely used in various complicated wounds. ObjectiveObserve the clinical efficacy of Recombinant human basic Fibroblast growth factor (rh-bFGF) applicated in the treatment of dog bite wounds. MethodsA total of 31 patients (16 adult and 15 aged) with rabies exposure grade Ⅲ dog bite wounds treated in the department of emergency surgery in our hospital from February 2020 to February 2022 were reviewed. Rh-bFGF was applied in the wounds after debridement and the patients were treated with preventive anti-inflammatory therapy. Observe the wound healing rules, infection rate, related complications and application time of antibiotics. ResultsEventually, all the wound were well healed and the healing time needed for most patients were about 2–3 weeks. The wound infection rate of aged patients was much higher, therefore application time of intravenous antibiotics injection in the aged patients was significantly higher than it in the adults (P < 0.05), but the difference of the time reach the intermittent wound dressing change was not statistically significant (P > 0.05). ConclusionRh-bFGF is safe and reliable for severe dog bite wounds in both the elderly and adults, it may help improve the early stage healing speed of aged patients, but the specific treatment needs to be individualized and accurate depends on different personal physique and wound conditions.

ODP178 Development and Validation of a Noncompetitive Immunoassay Optimized for the Assessment of Pharmacokinetics of Biologically Active Efruxifermin in Humans

Abstract Efruxifermin (EFX) is a novel fusion biotherapeutic consisting of two modified human fibroblast growth factor (FGF21) variants tethered via short linkers to a hIgG1 Fc domain. EFX is under clinical development by Akero Therapeutics, Inc. for treatment of non-alcoholic steatohepatitis (NASH). Fusion to the IgG Fc moiety extends the circulating half-life of EFX, enabling once-weekly subcutaneous administration. In addition, point mutations in the FGF21 moiety of EFX, relative to native human FGF21, protect against degradation of the C-terminus by the endogenous endopeptidase fibroblast activation protein (FAP), and increase affinity for the FGF21 co-receptor b-Klotho, which together enhance in vivo PD activity of EFX. Accordingly, to support clinical PK a sensitive and specific assay is needed for determination of biologically active (i. e., C-terminal intact) EFX serum concentrations that is minimally cross-reactive with endogenous FGF21 or potential inactive metabolites of EFX. Moreover, the assay needs to have reliability with serum samples from NASH patients, in whom hyperlipidemia and insulin resistance are prevalent. To achieve the analytical aims, we undertook development of a noncompetitive immunosorbent assay design, wherein a biotinylated version of a rat mAb directed against EFX's intact C-terminus serves as the capture reagent, while an affinity purified chicken anti-EFX pAb labeled with Sulfo-TAG functions as the detection reagent. This novel ECLIA design permits measurement of an electrochemiluminescence signal for maximizing assay sensitivity. In brief, serum samples are diluted 1: 10 in buffer and added to the MSD plate coated with rat mAb. After incubation and washing, bound EFX is detected using an affinity purified chicken anti-EFX PAB labeled with SULFO-TAG. After washing and addition of read buffer, the signal responses are measured in a SQ120 reader and concentration in test samples is estimated by dose-interpolation using a weighted 5-PL curve fit with an EFX standard curve ranging from 10–2,000 ng/mL. The new assay allows measurement of serum EFX at concentrations as low at 20 ng/mL. Upon pre-study validation, the assay has met analytical performance criteria outlined in BMV regulatory guidances. We conclude the optimized ECLIA will be useful for reliable assessment of EFX PK in patients with NASH. Presentation: No date and time listed

Myostatin is a negative regulator of adult neurogenesis after spinal cord injury in zebrafish.

Intrinsic and extrinsic inhibition of neuronal regeneration obstruct spinal cord (SC) repair in mammals. In contrast, adult zebrafish achieve functional recovery after complete SC transection. While studies of innate SC regeneration have focused on axon regrowth as a primary repair mechanism, how local adult neurogenesis affects functional recovery is unknown. Here, we uncover dynamic expression of zebrafish myostatin b (mstnb) in a niche of dorsal SC progenitors after injury. mstnb mutants show impaired functional recovery, normal glial and axonal bridging across the lesion, and an increase in the profiles of newborn neurons. Molecularly, neuron differentiation genes are upregulated, while the neural stem cell maintenance gene fgf1b is downregulated in mstnb mutants. Finally, we show that human fibroblast growth factor 1 (FGF1) treatment rescues the molecular and cellular phenotypes of mstnb mutants. These studies uncover unanticipated neurogenic functions for mstnb and establish the importance of local adult neurogenesis for innate SC repair.

Beneficial Effects of Oleosomes Fused with Human Fibroblast Growth Factor 1 on Wound Healing via the Promotion of Angiogenesis.

In our previous study, human fibroblast growth factor 1 was successfully fused with oleosomes, energy-storing organelles of seeds, which are considered to be excellent "expression carriers" for substances with a convenient purification process. The present work aimed to explore the beneficial effects of oleosomes fused with human fibroblast growth factor 1 (OLAF) on wound healing. The data showed marked improvements in terms of the angiogenesis, vascular integrity, collagen and inflammation on the wound sites of rats with a full-thickness skin defect. Moreover, the positive role of OLAF in promoting angiogenesis and its possible pathways were clarified in vivo and in vitro. The results showed that the number, length and branches of the blood vessels of the chick embryo chorioallantoic membrane were markedly increased after OLAF treatment. Meanwhile, the in vitro results also revealed that 100 ng/mL OLAF exhibited a promoting effect on the proliferation, migration and tube formation of human umbilical vein endothelial cells. In addition, the potential of OLAF to improve wound angiogenesis was demonstrated to be associated with an up-regulated PI3K/Akt pathway by transcriptome sequencing analysis and the introduction of a PI3K/Akt pathway inhibitor (LY294002). These findings suggest that OLAF has many prospects in the development of drugs for wound healing.

Poloxam Thermosensitive Hydrogels Loaded with hFGF2-Linked Camelina Lipid Droplets Accelerate Skin Regeneration in Deep Second-Degree Burns.

Burn injuries are difficult to manage due to the defect of large skin tissues, leading to major disability or even death. Human fibroblast growth factor 2 (hFGF2) is known to promote burn wound healing. However, direct administration of hFGF2 to the wound area would affect the bioactivity. To provide a supportive environment for hFGF2 and control its release in a steady fashion, in this research, we developed novel thermosensitive poloxam hydrogels delivered with hFGF2-linked Camelina lipid droplets (CLD-hFGF2 hydrogels). Cryopreserved scanning electron microscopy (SEM) results indicated that the incorporation of CLD-hFGF2 does not significantly affect the inner structure of hydrogels. The rheological properties showed that CLD-hFGF2 hydrogels gelated in response to temperature, thus optimizing the delivery method. In vitro, CLD-hFGF2 could be released from hydrogels for 3 days after drug delivery (the release rate was 72%), and the release solution could still promote the proliferation and migration of NIH3T3 cells. In vivo, compared with hydrogels alone or with direct CLD-hFGF2 administration, CLD-hFGF2 hydrogels had the most obvious effect on deep second-degree burn wound healing. This work indicates that CLD-hFGF2 hydrogels have potential application value in burn wound healing.

Free-standing multilayer films as growth factor reservoirs for future wound dressing applications

Chronic skin wounds place a high burden on patients and health care systems. The use of angiogenic and mitogenic growth factors can facilitate the healing but growth factors are quickly inactivated by the wound environment if added exogenously. Here, free-standing multilayer films (FSF) are fabricated from chitosan and alginate as opposing polyelectrolytes in an alternating manner using layer-by-layer technique. One hundred bilayers form an about 450 μm thick, detachable free-standing film that is subsequently crosslinked by either ethyl (dimethylaminopropyl) carbodiimide combined with N-hydroxysuccinimide (E-FSF) or genipin (G-FSF). The characterization of swelling, oxygen permeability and crosslinking density shows reduced swelling and oxygen permeability for both crosslinked films compared to non-crosslinked films (N-FSF). Loading of fibroblast growth factor 2 (FGF2) into the films results in a sustained release from crosslinked FSF in comparison to non-crosslinked FSF. Biocompatibility studies in vitro with human dermal fibroblasts cultured underneath the films demonstrate increased cell growth and cell migration for all films with and without FGF2. Especially G-FSF loaded with FGF2 greatly increases cell proliferation and migration. In vivo biocompatibility studies by subcutaneous implantation in mice show that E-FSF causes an inflammatory tissue response that is absent in the case of G-FSF. N-FSF also represents a biocompatible film but shows early degradation. All FSF possess antibacterial properties against gram+ and gram- bacteria demonstrated by an agar diffusion disc assay. In summary, FSF made of alginate and chitosan crosslinked with genipin can act as a reservoir for the sustained release of FGF2, possessing high biocompatibility in vitro and in vivo. Moreover, G-FSF promotes growth and migration of human dermal fibroblasts and has antibacterial properties, which makes it an interesting candidate for bioactive wound.

Supplement of secreted recombinant low molecular weight human fibroblast growth factor 2 in culture media enhances in vitro bovine maturation

With the annual increase in in vitro bovine embryo production, understanding oocyte maturation is becoming more important. Previous studies have shown that oocyte maturation can be improved by adding bovine additives to in vitro maturation media. Among the additives, human fibroblast growth factor 2 (hFGF2) is well known for its positive influence on the growth rate and quality of cells and oocytes. However, the effect of LMW-hFGF2, one of the isoforms of hFGF2, on bovine in vitro maturation has not yet been identified. Therefore, the goal of this study was to elucidate the effect of LMW-hFGF2 on bovine oocyte maturation. Vectors expressing LMW-hFGF2 were cloned and transfected into cells. Afterward, secretion of LMW-hFGF2 from cells was confirmed, and used to assess the effect LMW-hFGF2 on cells and bovine oocytes. LMW-hFGF2 improved bovine oocyte maturation and embryo developmental competence. Laboratories can use LMW-hFGF2 in bovine oocyte culture media to improve in vitro embryo production success rates.

Do Sugar-Sweetened Beverages Increase Fasting FGF21 Irrespective of the Type of Added Sugar? A Secondary Exploratory Analysis of a Randomized Controlled Trial.

Human fibroblast growth factor 21 (FGF21) is a multifaceted metabolic regulator considered to control sugar intake and to exert beneficial effects on glucose and lipid metabolism. Elevated serum FGF21 levels are associated with metabolic syndrome, suggesting a state of FGF21 resistance. Further, given the evidence of a hepatic ChREBP and FGF21 signaling axis, it can be assumed that SSBs containing fructose would possibly increase FGF21 concentrations. We investigated the effects of sugar-sweetened beverage (SSB) consumption on fasting FGF21 levels in healthy, lean men, discriminating the effects of glucose, fructose, and their disaccharide sucrose by secondary data analysis from a randomized controlled trial. Seven weeks of daily SSB consumption resulted in increased fasting FGF21 in healthy, lean men, irrespective of the sugar type. Medians of ΔFGF21 between post-SSB intervention values (week 7) and no-intervention period values (IQR) in pg/mL were: glucose 17.4 (0.4–45.8), fructose 22.9 (−8.6–35.1), and sucrose 13.7 (2.2–46.1). In contrast, this change in FGF21 concentration was only 6.3 (−20.1–26.9) pg/mL in the control group. The lack of a fructose-specific effect on FGF21 concentrations is contrary to our assumption. It is concluded that SSB intake may impact FGF21 concentrations and could contribute to the increased FGF21 concentrations observed in subjects suffering from metabolic syndrome that is possibly associated with decreased FGF21 responsiveness.

One-step metal affinity purification of recombinant hFGF19 without using tags

Human fibroblast growth factor 19 (hFGF19) belongs to the endocrine FGF19 superfamily and is considered a potential agent to treat severe or relapsing nonalcoholic fatty liver disease. Numerous studies have confirmed the beneficial effects of this hormone on the related symptoms of the disease and attempts at producing recombinant proteins in various hosts are steadily proliferating. Recently, we reported that authentic hFGF19 can be solubly expressed through combining synonymous codon substitutions and co-expression with disulfide-bond isomerase (DsbC) in Escherichia coli. However, during purification, hFGF19 without the His-tag occasionally co-eluted with His-tagged DsbC when using metal affinity chromatography, thereby requiring auxiliary purification steps to achieve apparent homogeneity. This phenomenon provides evidence that hFGF19 specifically interacts with immobilized Ni2+, which can thus be used as an alternative tool for the purification of hFGF19. Consequently, we could simply and reproducibly purify hFGF19 from cell lysates by using Ni2+-immobilized metal affinity chromatography and stepwise gradient elution with imidazole.

High-level transient production of a protease-resistant mutant form of human basic fibroblast growth factor in Nicotiana benthamiana leaves.

The human basic fibroblast growth factor (bFGF) is a protein that plays a pivotal role in cellular processes like cell proliferation and development. As a result, it has become an important component in cell culture systems, with applications in biomedical engineering, cosmetics, and research. Alternative production techniques, such as transient production in plants, are becoming a feasible option as the demand continues to grow. High-level bFGF production was achieved in this study employing an optimized Agrobacterium-mediated transient expression system, which yielded about a 3-fold increase in production over a conventional system. This yield was further doubled at about 185 µg g-1 FW using a mutant protease-resistant version that degraded/aggregated at a three-fold slower rate in leaf crude extracts. To achieve a pure product, a two-step purification technique was applied. The capacity of the pure protease-resistant bFGF (PRbFGF) to stimulate cell proliferation was tested and was found to be comparable to that of E. coli-produced bFGF in HepG2 and CHO-K1 cells. Overall, this study demonstrates a high-level transient production system of functional PRbFGF in N. benthamiana leaves as well as an efficient tag-less purification technique of leaf crude extracts.

Effect of the combination of composite skin grafting and recombinant human basic fibroblast growth factor on plastic surgery for extensive sc ars after burns

Purpose: To investigate the effect of combined use of composite skin grafting and recombinant human basic fibroblast growth factor (rh-bFGF) on plastic surgery for extensive burn scars, and its influence on wound healing and inflammatory responses in patients.&#x0D; Methods: Hospital records of 120 patients who underwent extensive scar plastic surgery after burns in Hanchuan People’s Hospital from February 2019 to February 2020 were retrospectively analyzed. The patients were equally assigned to study group (STG) and control group (COG), based on the order of admission. All patients received composite skin grafting surgery and post-surgery topical silver sulphadiazine cream regularly, while those in study group (STG) received additional treatment with rh-bFGF spray on the wound surfaces. Scar scores, degree of wound healing, populations of fibrocytes and capillaries, levels of vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1), and activities of lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) were evaluated.&#x0D; Results: Patients in STG had significantly better scar scores, shorter mean wound healing time, higher mean degree of wound healing, higher scores on inflammatory reactions near the wounds, and higher populations of fibrocytes and capillaries, when compared with patients in COG group (p &lt; 0.001). After surgery, there were lower levels of VEGF and TGF-β1, and lower levels of activities of LDH and SDH in STG than in COG group (p &lt; 0.001).&#x0D; Conclusion: Rh-bFGF accelerates the proliferation of wound tissue, improves local microcirculation, regulates inflammatory response, and enhances wound healing in burn scar patients when used in combination with composite skin grafting. Therefore, Rh-bFGF has a potential for enhanced management of burn scars.

Expression, purification and bioactivity analysis of a recombinant fusion protein rHSA-hFGF21 in Pichia pastoris

Human fibroblast growth factor 21 (hFGF21) has become a candidate drug for regulating blood glucose and lipid metabolism. The poor stability and short half-life of hFGF21 resulted in low target tissue availability, which hampers its clinical application. In this study, the hFGF21 was fused with a recombinant human serum albumin (HSA), and the resulted fusion protein rHSA-hFGF21 was expressed in Pichia pastoris. After codon optimization, the recombinant gene fragment rHSA-hFGF21 was inserted into two different vectors (pPIC9k and pPICZαA) and transformed into three different strains (X33, GS115 and SMD1168), respectively. We investigated the rHSA-hFGF21 expression levels in three different strains and screened an engineered strain X33-pPIC9K-rHSA-hFGF21 with the highest expression level. To improve the production efficiency of rHSA-hFGF21, we optimized the shake flask fermentation conditions, such as the OD value, methanol concentration and induction time. After purification by hollow fiber membrane separation, Blue affinity chromatography and Q ion exchange chromatography, the purity of the rHSA-hFGF21 protein obtained was 98.18%. Compared to hFGF21, the biostabilities of rHSA-hFGF21, including their resistance to temperature and trypsinization were significantly enhanced, and its plasma half-life was extended by about 27.6 times. Moreover, the fusion protein rHSA-hFGF21 at medium and high concentration showed a better ability to promote glucose uptake after 24 h of stimulation in vitro. In vivo animal studies showed that rHSA-hFGF21 exhibited a better long-term hypoglycemic effect than hFGF21 in type 2 diabetic mice. Our results demonstrated a small-scale production of rHSA-hFGF21, which is important for large-scale production and clinical application in the future.

3D-Printed Gelatin-Alginate Hydrogel Dressings for Burn Wound Healing: A Comprehensive Study.

Burn wound treatment is still a clinical challenge due to the severity of tissue damage and dehydration. Among various wound dressings, hydrogel materials have gained significant attention for burn wound treatment in clinical practice due to their soothing and moisturizing activity. In this study, 3D-printed dressings were fabricated using clinically relevant hydrogels for deep partial-thickness burn (PTB) wounds. Different ratios of gelatin and alginate mixture were 3D-printed and examined in terms of rheological behavior, shear thinning behavior, mechanical properties, degradation rate, and hydration activity to tune the hydrogel composition for best functionality. The cell-laden dressings were bioprinted to evaluate the effect of the gelatin: alginate ratio on the proliferation and growth of human dermal fibroblasts. The present findings confirm that the higher alginate content is associated with higher viscosity and Young's modulus, while higher gelatin content is associated with faster degradation and higher cell viability. Together, the 3D-printed dressing with 75% gelatin and 25% alginate showed the best tradeoff between mechanical properties, hydration activity, and in vitro biological response. Findings from in vivo test using the most effective dressing showed the positive effect of 3D-printed porous pattern on wound healing, including faster wound closure, regenerated hair follicles, and non-traumatic dressing removal compared to the non-printed hydrogel with the same composition and the standard of care. Results from this research showed that 3D-printed dressings with an adequate gelatin: alginate ratio enhanced wound healing activity for up to 7 days of moisture retention on deep PTB wounds.

Hyaluronan/Zinc Oxide Nanocomposite-Based Membrane: Preparation, Characterization, and In Vitro and In Vivo Evaluation

Hyaluronic acid (HA) has attracted the attention of scientists for its application in many medical fields owing to its intrinsic properties such as biodegradability, biocompatibility, and nontoxicity. Poor stability and antibacterial activity are the most significant drawbacks of using HA in preparing a wound dressing. The wound dressing should be able to swell and absorb exudates from the wound, as well as possess antibacterial activity. Herein, we successfully prepared an HA-based antibacterial wound dressing that can swell more than 500 times and with good mechanical properties. HA was used both as reducing and stabilizing agents, and zinc oxide nanoparticles (ZnO-NPs) were incorporated via in situ synthesis. The uniform spherical shape of ZnO-NPs (50 ± 10 nm) was synthesized and assembled on a hyaluronan/polyvinyl alcohol matrix (HA/PVA), forming stable and evenly distributed ZnO-NPs, which interacted with the HA/PVA. Such a hybrid nanostructure prevented ZnO-NPs from dropping off the PVA/HA network and thus minimized the toxicity of NPs. Concerning the slow release of NPs, the nanocomposite membrane still exhibited significant antibacterial activity against different types of bacteria (G+/−). The ZnO-NPs/HA/PVA composite membrane allows the attachment and growth of normal human dermal fibroblasts and human primary osteogenic sarcoma (Saos-2) without exhibiting toxicity. In vivo measurements showed that the nanocomposite PVA/HA/ZnO-NP membrane promoted infected wound healing compared with the control sample. The results obtained suggest that the investigated nanocomposite has reasonable potential as an antibacterial wound dressing material.