Fibroblast Adhesion Research Articles

Tailoring Cell Attachment onto Melt Electrowritten Scaffolds via a Phase Separated Hydrogel Coating with Peptide Functionalization

AbstractHighly porous scaffolds with a high surface area can be designed and fabricated via melt electrowriting (MEW). Here, the study introduces morphological features onto the MEW microfibers via a hydrogel coating of phase‐separated poly(2‐hydroxyethyl methacrylate) (pHEMA). This coating is achieved by capturing phase‐separated droplets of pHEMA onto poly(ε‐caprolactone) (PCL) microfibers via dip‐coating, resulting in a hydrogel coating with webbed structures across pores of the MEW scaffold. Excess pHEMA droplets are removed and phase separation is quenched by washing in water, and then functionalized by dipping the pHEMA coated scaffold into a buffered peptide solution. It is demonstrated that a cysteine‐terminated peptide sequence (Cys‐Gly‐Arg‐Gly‐Asp‐Ser‐Gly (CG‐RGD‐SG)) promotes fibroblast adhesion on the hydrogel‐coated MEW scaffolds compared to unmodified pHEMA and compared to scrambled peptide sequence. Due to the protein‐resistant nature of pHEMA, the hydrogel‐coated scaffolds show less cell attachment than non‐coated PCL scaffolds, while RGD‐functionalized pHEMA scaffolds achieve 2.8‐fold increase in cell attachment (p = 0.02) when compared to non‐functionalized pHEMA. The study therefore presents a platform that combines PCL scaffolds of microscale fibers with a phase‐separated pHEMA hydrogel coating that maintains the high porosity of MEW scaffolds yet increases surface area and, importantly, introduces the capability for tailoring cell attachment via peptide functionalization.

Thermoresponsive Brush Coatings for Cell Sheet Engineering with Low Protein Adsorption above the Polymers' Phase Transition Temperature.

Thermoresponsive polymer coatings on cell culture substrates enable noninvasive cell detachment and cell sheet fabrication for biomedical applications. Optimized coatings should support controlled culture and detachment of various cell types and allow chemical modifications, e.g., to introduce specific growth factors for enhanced gene expression. Furthermore, the sterilization and storage stability of the coatings must be assessed for translational attempts. Poly(glycidyl ether) (PGE) brush coatings with short alkoxy side chains provide a versatile platform for cell culture and detachment, but their polyether backbones are susceptible to oxidation and degradation. Thus, we rationally designed potential alternatives with thermoresponsive glycerol-based block copolymers comprising a stable polyacrylate or polymethacrylate backbone and an oligomeric benzophenone (BP)-based anchor. The resulting poly(ethoxy hydroxypropyl acrylate-b-benzophenone acrylate) (pEHPA-b-BP) and poly(ethoxy hydroxypropyl methacrylate-b-benzophenone methacrylate) (pEHPMA-b-BP) block copolymers preserve the short alkoxy-terminated side chains of the PGE derived structure on a stable, but hydrophobic, aliphatic backbone. The amphiphilicity balance is maintained through incorporated hydroxyl groups, which simultaneously can be used for chemical modification. The polymers were tailored into brush coatings on polystyrene surfaces via directed adsorption using the BP oligomer anchor. The resulting coatings with thickness values up to ∼3 nm supported efficient adhesion and proliferation of human fibroblasts despite minimal protein adsorption. The conditions for cell sheet fabrication on pEHPA-b-BP were gentler and more reliable than on pEHPMA-b-BP, which required additional cooling. Hence, the stability of pEHPA-b-BP and PGE coatings was evaluated post gamma and formaldehyde (FO) gas sterilization. Gamma sterilization partially degraded PGE coatings and hindered cell detachment on pEHPA-b-BP. In contrast, FO sterilization only slowed detachment on PGE coatings and had no adverse effects on pEHPA-b-BP, maintaining their efficient performance in cell sheet fabrication.

Knockdown of ANO1 decreases TGF-β- and IL-6-induced adhesion and migration of cardiac fibroblasts by inhibiting the expression of integrin and focal adhesion kinase

Ischemic cardiac injury triggers a significant inflammatory response, activating and mobilizing cardiac fibroblasts (CFs), which ultimately contributes to myocardial fibrosis. In this study, we investigated the role of ANO1, a calcium-activated chloride channel (CaCC) protein, in regulating CFs migration and adhesion under inflammatory conditions. Our results demonstrated that ANO1 knockdown significantly attenuated TGF-β- and IL-6-induced adhesion and migration of CFs. This inhibitory effect was mediated through the downregulation of integrin expression and reduced activation of focal adhesion kinase (FAK), key components in cellular adhesion and motility pathways. This study provides new insights into the mechanisms underlying CFs migration and adhesion, highlighting the potential of ANO1 as a therapeutic target for mitigating adverse fibrotic remodeling following myocardial infarction.

Effect of Bioplastic Material on Adhesion, Growth, and Proliferative Activity of Human Fibroblasts When Incubated in Solutions Mimic the Acidity of Wound an Acute and Chronic Inflammation.

: The aim of this study was to characterize the effect of bioplastic material based on collagen, hyaluronic acid, and elastin on the viability and proliferative activity of human fibroblasts in conditions simulating the acidity of acute and chronic wounds. : Bioplastic material was made according to the method described in RF patent no.2722744. Adhesive properties and proliferative activity of human fibroblasts were assessed visually using fluorescent microscopy. The number of apoptotic and necrotic cells was assessed by flow cytometry (BD FACSCanto II) using the commercial FITC Annexin V Apoptosis Detection Kit I (BD Pharmingen). The strength, Young's modulus, and elasticity of the gels were determined on a TA.XT-plus texture analyzer (Stable Micro Systems, Great Britain). : Using the methods of luminescent microscopy and flow cytometry, we found that the cell viability (namely, adhesive properties and proliferative activity) decreases after incubation on condition mimic of physiological acidosis. We found that bioplastic material contributes to the preservation of adhesive properties, viability, and proliferative activity of fibroblasts in physiological acidosis conditions. The results obtained indicate that bioplastic material based on soluble dermis components can be used as a biologically active component of wound dressings to increase the effectiveness of reparative regeneration, especially in cases of excessive acute inflammation.

Poly(HEMA-co-MMA) Hydrogel Scaffold for Tissue Engineering with Controllable Morphology and Mechanical Properties Through Self-Assembly

Poly(2-hydroxyethyl methacrylate) (PHEMA) has been widely used in medical materials for several decades. However, the poor mechanical properties of this material have limited its application in the field of tissue engineering. The purpose of this study was to fabricate a scaffold with suitable mechanical properties and in vitro cell responses for soft tissue by using poly(HEMA-co-MMA) with various concentration ratios of hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA). To customize the concentration ratio of HEMA and MMA, the characteristics of the fabricated scaffold with various concentration ratios were investigated through structural morphology, FT-IR, mechanical property, and contact angle analyses. Moreover, in vitro cell responses were observed according to the various concentration ratios of HEMA and MMA. Consequently, various morphologies and pore sizes were observed by changing the HEMA and MMA ratio. The mechanical properties and contact angle of the fabricated scaffolds were measured according to the HEMA and MMA concentration ratio. The results were as follows: compressive maximum stress: 254.24–932.42 KPa; tensile maximum stress: 4.37–30.64 KPa; compressive modulus: 16.14–38.80 KPa; tensile modulus: 0.5–2 KPa; and contact angle: 36.89–74.74°. In terms of the in vitro cell response, the suitable cell adhesion and proliferation of human dermal fibroblast (HDF) cells were observed in the whole scaffold. Therefore, a synthetic hydrogel scaffold with enhanced mechanical properties and suitable fibroblast cell responses could be easily fabricated for use with soft tissue using a specific HEMA and MMA concentration ratio.

The Effect of Platelet Fibrin Plasma (PFP) on Postoperative Refractory Wounds: Physiologically Concentrated Platelet Plasma in Wound Repair.

Surgical wounds that can't complete primary healing three weeks after surgery are called postoperative refractory wounds. Postoperative refractory wounds would bring great physical and life burdens to the patients and seriously affect their quality of life. To investigate the effect of platelet fibrin plasma (PFP) on postoperative refractory wound healing. The composition of PFP was analyzed using blood routine and blood biochemicals. Clinical data were collected that met the inclusion criteria after treatment with PFP, and the efficacy of PFP was evaluated by wound healing rate and days to healing. Next, growth factor content in PFP, PRP, and PPP was analyzed using ELISA, and PFP-treated cells were applied to investigate the effect of PFP on fibroblast and endothelial cell function. PFP component analysis revealed no statistical difference between platelet concentration in PFP and physiological concentration. Clinical statistics showed that PFP treatment was effective in the postoperative refractory wound (four-week wound healing rate > 90%), significantly better than continuous wound dressing. Meanwhile, our result also proved that PFP treatment significantly enhanced vascularization by upregulated the expression level of CD31 and improved granulation tissue thickness. Activated PFP, PRP, and PPP could continuously release growth factors in vitro and the amount of growth factors released by PRP and PFP was significantly higher than PPP. In vitro studies demonstrated that active PFP could improve cell proliferation, migration, adhesion, and angiogenesis in fibroblasts and endothelial cells. Physiologically concentrated platelet plasma promoted wound healing and improved related cellular functions. The modified PFP (responsible for accelerating wound healing and enhancing the migration and proliferation of fibroblasts and endothelial cells) was prepared and analyzed for its clinical effectiveness in postoperative refractory wounds. Physiologically concentrated platelet plasma promoted wound healing and improved related cellular functions. The preparation of PFP could significantly reduce the amount of prepared blood, with a good application value for postoperative wounds. PFP can be considered a treatment option, especially for postoperative refractory wounds.

Changes in gene expression profile of normal human fibroblasts on P(VDF-TrFE) scaffolds highly doped with Fe3O4-CA nanoparticles under alternating magnetic field stimulation

The design of novel hybrid magnetoactive scaffolds based on biocompatible piezopolymers and magnetic nanoparticles is of interest for medicine, mainly for tissue regeneration, because application of an external either static or alternating magnetic field to cells that settled on a magnetoactive scaffold offers an opportunity for remote control of cellular functions. This study describes fabrication of electrospun magnetoactive poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] scaffolds highly doped with 20 wt% of magnetite nanoparticles modified with citric acid (Fe3O4-CA). The electrospun P(VDF-TrFE)/Fe3O4-CA scaffolds have defect-free morphology with a fiber diameter of approximately 1 μm and contain both an electroactive β-phase (predominantly) and a lesser amount of an γ-phase. A high content of uniformly distributed Fe3O4-CA nanoparticles within P(VDF-TrFE) fibrous scaffolds resulted in a high saturation magnetization of 12.1 emu/g and ferrimagnetic behavior of the composite P(VDF-TrFE)/Fe3O4-CA scaffolds. They were proved to be biocompatible with normal human cells: normal human fibroblasts and human mesenchymal stem cells adhered to the scaffold and retained their viability. According to high-throughput RNA-sequencing data, the adhesion of fibroblasts to the scaffolds upregulated genes related to key stages of tissue regeneration such as coagulation (genes THBD and SERPINB2) and wound healing (IL24, PDGFB, F3, and PLAU) and affected TGFβ, BMP, and Wnt signaling pathways. Alternating-magnetic-field exposure of the magnetoactive P(VDF-TrFE)/Fe3O4-CA scaffolds with fibroblasts settled on the surface activated extracellular and intracellular cell signaling pathways.

Effect of Er,Cr:YSGG Laser Irradiation on the Surface Modification and Cell Adhesion on Titanium Discs: An In Vitro Study

This study evaluates the potential of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation to modify the titanium surface for optimal seeding of fibroblasts and osteoblasts in the treatment of peri-implantitis. Titanium discs were treated using the Er,Cr:YSGG laser, an ultrasonic device with a stainless tip, or titanium scalers. Changes in surface properties were analyzed by profilometer and scanning electron microscopy (SEM). Murine fibroblast and osteoblast adhesion and proliferation were evaluated qualitatively and quantitatively at 24 and 72 h. Profilometric surface topography and SEM showed that titanium scalers and ultrasonic debridement techniques significantly changed the structure of the machined and rough titanium surfaces. The Er,Cr:YSGG laser irradiation, on the other hand, did not alter titanium microstructures. The Er,Cr:YSGG laser irradiation with the 40 Hz group showed a significantly higher attached fibroblast cell numbers than the titanium scaler group at 72 h after treatment (p = 0.023). Additionally, the number of the attached osteoblasts in the Er,Cr:YSGG laser irradiation with the 40 Hz group was significantly higher than that of the no-treatment groups 24 h after treatment (p = 0.045). The Er,Cr:YSGG laser effectively promoted adherence of fibroblasts and osteoblasts to the titanium surface without significantly altering the titanium surface, suggesting its superiority for treating peri-implantitis.

Design and development of large-diameter Mg-Zn-Ca bulk metallic glass for biomedical applications: A mechanical and corrosion perspective

Being amorphous, bulk metallic glasses (BMGs) exhibit superior properties compared to their crystalline alloy counterparts. Amorphous materials are preferred for their excellent mechanical and degradation behavior. Among the various elemental combinations, MgZnCa has shown the most promising results, as evidenced by the literature. However, the maximum achievable size of the metallic glasses remains a bottleneck. The current work aims to address this challenge and achieve it splendidly with a systematic methodology by developing larger diameter MgZnCa BMGs through vacuum induction casting using a specially designed copper mold. The optimal composition was formalized for glass formation of the Mg65Zn31Ca4 system using the CALPHAD technique. As a result, a 6.5 mm diameter glassy alloy was successfully obtained. The XRD and TEM analysis experiments demonstrated a perfect amorphous structure of the developed sample. The anti-corrosion properties of the as-cast glass increased, followed by enhancement in the yield strength and hardness in contrast to the properties of the human bone. Furthermore, the surface wettability analysis showed an adequate surface obtained to promote fibroblast adhesion. In conclusion, the current work represents a notable progress in the fabrication of larger-diameter MgZnCa BMG for biomedical applications, considering that the biggest diameter ever reported in the MgZnCa system was more than a decade ago.

Decellularized extracellular matrix derived from dental pulp stem cells promotes gingival fibroblast adhesion and migration

BackgroundDecellularized extracellular matrix (dECM) has been proposed as a useful source of biomimetic materials for regenerative medicine due to its biological properties that regulate cell behaviors. The present study aimed to investigate the influence of decellularized ECM derived from dental pulp stem cells (DPSCs) on gingival fibroblast (GF) cell behaviors. Cells were isolated from dental pulp and gingival tissues. ECM was derived from culturing dental pulp stem cells in growth medium supplemented with ascorbic acid. A bioinformatic database of the extracellular matrix was constructed using Metascape. GFs were reseeded onto dECM, and their adhesion, spreading, and organization were subsequently observed. The migration ability of the cells was determined using a scratch assay. Protein expression was evaluated using immunofluorescence staining.ResultsType 1 collagen and fibronectin were detected on the ECM and dECM derived from DPSCs. Negative phalloidin and nuclei were noted in the dECM. The proteomic database revealed enrichment of several proteins involved in ECM organization, ECM–receptor interaction, and focal adhesion. Compared with those on the controls, the GFs on the dECM exhibited more organized stress fibers. Furthermore, cultured GFs on dECM exhibited significantly enhanced migration and proliferation abilities. Interestingly, GFs seeded on dECM showed upregulation of FN1, ITGB3, and CTNNB1 mRNA levels.ConclusionsECM derived from DSPCs generates a crucial microenvironment for regulating GF adhesion, migration and proliferation. Therefore, decellularized ECM from DPSCs could serve as a matrix for oral tissue repair.

Galectin-3/Gelatin Electrospun Scaffolds Modulate Collagen Synthesis in Skin Healing but Do Not Improve Wound Closure Kinetics.

Chronic wounds remain trapped in a pro-inflammatory state, with strategies targeted at inducing re-epithelialization and the proliferative phase of healing desirable. As a member of the lectin family, galectin-3 is implicated in the regulation of macrophage phenotype and epithelial migration. We investigated if local delivery of galectin-3 enhanced skin healing in a full-thickness excisional C57BL/6 mouse model. An electrospun gelatin scaffold loaded with galectin-3 was developed and compared to topical delivery of galectin-3. Electrospun gelatin/galectin-3 scaffolds had an average fiber diameter of 200 nm, with 83% scaffold porosity approximately and an average pore diameter of 1.15 μm. The developed scaffolds supported dermal fibroblast adhesion, matrix deposition, and proliferation in vitro. In vivo treatment of 6 mm full-thickness excisional wounds with gelatin/galectin-3 scaffolds did not influence wound closure, re-epithelialization, or macrophage phenotypes, but increased collagen synthesis. In comparison, topical delivery of galectin-3 [6.7 µg/mL] significantly increased arginase-I cell density at day 7 versus untreated and gelatin/galectin-3 scaffolds (p < 0.05). A preliminary assessment of increasing the concentration of topical galectin-3 demonstrated that at day 7, galectin-3 [12.5 µg/mL] significantly increased both epithelial migration and collagen content in a concentration-dependent manner. In conclusion, local delivery of galectin 3 shows potential efficacy in modulating skin healing in a concentration-dependent manner.

Internally-crosslinked alginate dialdehyde/alginate/gelatin-based hydrogels as bioprinting inks for prospective cardiac tissue engineering applications

Cardiovascular diseases represent a worldwide social and economic challenge, due to heart tissue limited regenerative capabilities. 3D bioprinted cell-laden constructs are a promising approach to develop patches for cardiac regeneration or in vitro models for new drug preclinical discovery and validation. However, the development of bioinks with optimal mechanical, rheological, and biological properties is still a challenge. Although alginate (Alg)-based bioinks have been extensively explored, such hydrogels lack cell adhesion properties and degradability. Additionally, 3D Alg structures are usually obtained by micro-extrusion bioprinting exploiting conventional external cross-linking methods, which introduce inhomogeneities and unpredictability in construct formation. This work exploits Alg internal ionic gelation mechanism to obtain homogeneous self-standing multilayered 3D printed constructs without employing support baths or post-printing crosslinking treatments, combining an insoluble calcium salt (calcium carbonate, CaCO3) with an acidifying agent (D-(+)-Glucono-1,5-lactone, GDL) to promote controlled release of calcium ions. Alg was blended with oxidized alginate (ADA) and gelatin (Gel) to achieve degradable and cell adhesive hydrogels for cardiac tissue engineering. Firstly, ADA/Alg bioink composition was tailored by varying polymer weight ratio (keeping ADA as the main component) and calcium ions concentration to achieve cardiac tissue-like viscoelastic properties. Then, the amount of Gel in ADA/Alg hydrogels was optimized to support adult human cardiac fibroblasts (AHCFs) adhesion, producing shear thinning inks with tunable viscoelastic properties (G&amp;rsquo; 650-1300 Pa) and degradation profile (40-80% weight loss after 21 days in phosphate buffered saline, PBS) by varying Gel concentration. ADA/Alg/Gel hydrogels showed a shear thinning behavior suitable for 3D bioprinting and dependent on ink stabilization time, due to the gradual pH-triggered release of calcium ions over time. AHCFs-laden ADA/Alg/Gel bioinks could be successfully printed producing scaffolds with high shape fidelity and good cell viability post-printing. Finally, 3D AHCF-laden and H9C2-laden ADA/Alg/Gel bioinks with the highest gelatin content (25% w/w) allowed cell adhesion after 24 hours of incubation, showing potential application for cardiac tissue modelling. This research presented a comprehensive framework for advancing the design of bioink formulations enabling the printing of cell-adhesive and self-supporting constructs.

Mast cells: a double-edged sword in inflammation and fibrosis.

As one of the key components of the immune system, mast cells are well known for their role in allergic reactions. However, they are also involved in inflammatory and fibrotic processes. Mast cells participate in all the stages of acute inflammatory responses, playing an immunomodulatory role in both innate and adaptive immunity. Mast cell-derived histamine, TNF-α, and IL-6 contribute to the inflammatory processes, while IL-10 mediates the suppression of inflammation. Crosstalk between mast cells and other immune cells is also involved in the development of inflammation. The cell-cell adhesion of mast cells and fibroblasts is crucial for fibrosis. Mast cell mediators, including cytokines and proteases, play contradictory roles in the fibrotic process. Here, we review the double-edged role of mast cells in inflammation and fibrosis.

Low-temperature DLP 3D printing of low-concentration collagen methacryloyl for the fabrication of durable and bioactive personalized scaffolds

Digital Light Processing (DLP) bioprinting has revolutionized tissue engineering and regenerative medicine with its speed and precision. Although commonly used in DLP printing, Gelatin Methacrylate (GelMA) lacks the mechanical strength and complex biological signaling of collagen, owing to the absence of collagen’s unique triple helix structure. However, collagen faces challenges such as denaturation at high temperatures and aggregation at neutral pH, limiting its use as a bioink. Herein, we present for the first time the development of a low-temperature DLP 3D printing technique using low-concentration Collagen Methacryloyl (ColMA) for fabricating durable and bioactive personalized scaffolds. Our study shows that pH significantly influences ColMA printing, with pH 3 producing low-concentration scaffolds that exhibit enhanced mechanical properties, minimal swelling, and prolonged resistance to enzymatic hydrolysis compared to high-concentration GelMA scaffolds, while low-concentration GelMA cannot be printed independently. ColMA scaffolds notably boost the proliferation, adhesion, migration, and differentiation of human foreskin fibroblasts. In vivo rat model tests demonstrate that ColMA scaffolds reduce inflammation, enhance collagen deposition, and accelerate epidermal regeneration. This method offers a robust solution for low-temperature DLP 3D printing of collagen ink, facilitating the creation of personalized scaffolds with superior bioactivity and representing a significant advancement in tissue engineering applications.

Comparison In Vitro Study on the Interface between Skin and Bone Cell Cultures and Microporous Titanium Samples Manufactured with 3D Printing Technology Versus Sintered Samples.

Percutaneous implants osseointegrated into the residuum of a person with limb amputation need to provide mechanical stability and protection against infections. Although significant progress has been made in the biointegration of percutaneous implants, the problem of forming a reliable natural barrier at the level of the surface of the implant and the skin and bone tissues remains unresolved. The use of a microporous implant structure incorporated into the Skin and Bone Integrated Pylon (SBIP) should address the issue by allowing soft and bone tissues to grow directly into the implant structure itself, which, in turn, should form a reliable barrier to infections and support strong osseointegration. To evaluate biological interactions between dermal fibroblasts and MC3T3-E1 osteoblasts in vitro, small titanium discs (with varying pore sizes and volume fractions to achieve deep porosity) were fabricated via 3D printing and sintering. The cell viability MTT assay demonstrated low cytotoxicity for cells co-cultured in the pores of the 3D-printed and sintered Ti samples during the 14-day follow-up period. A subsequent Quantitative Real-Time Polymerase Chain Reaction (RT-PCR) analysis of the relative gene expression of biomarkers that are associated with cell adhesion (α2, α5, αV, and β1 integrins) and extracellular matrix components (fibronectin, vitronectin, type I collagen) demonstrated that micropore sizes ranging from 200 to 500 µm of the 3D printed and sintered Ti discs were favorable for dermal fibroblast adhesion. For example, for representative 3D-printed Ti sample S6 at 72 h the values were 4.71 ± 0.08 (α2 integrin), 4.96 ± 0.08 (α5 integrin), 4.71 ± 0.08 (αV integrin), and 1.87 ± 0.12 (β1 integrin). In contrast, Ti discs with pore sizes ranging from 400 to 800 µm demonstrated the best results (in terms of marker expression related to osteogenic differentiation, including osteopontin, osteonectin, osteocalcin, TGF-β1, and SMAD4) for MC3T3-E1 cells. For example, for the representative 3D sample S4 on day 14, the marker levels were 11.19 ± 0.77 (osteopontin), 7.15 ± 0.29 (osteonectin), and 6.08 ± 0.12 (osteocalcin), while for sintered samples the levels of markers constituted 5.85 ± 0.4 (osteopontin), 4.45 ± 0.36 (osteonectin), and 4.46 ± 0.3 (osteocalcin). In conclusion, the data obtained show the high biointegrative properties of porous titanium structures, while the ability to implement several pore options in one structure using 3D printing makes it possible to create personalized implants for the best one-time integration with both skin and bone tissues.

Design of multiple-function matrix encapsulated with Marjoram extract to support cellular functions, stimulate collagen synthesis and decrease infection in wound

This study aimed to assess the role of the combination of design techniques of the engineered substrates, and the effect of encapsulating Marjoram (Origanum Majorana L.) into the matrix network was studied. To this end, PVA-PEG matrices were designed through 3 techniques of freeze–thaw (FT), the combination of both methods of freeze-drying and freeze-thawing(FT-FD), and ternary technique(freeze-drying,freeze-thawing,cross-linking(FT-FD/CL)), by combining equal volume ratios of both polymers. The results indicated the ternary technique can provide better physicochemical properties(porosity: 96%, lower degradation rate, higher modulus) compared to FT and FT-FD methods. Afterward, encapsulation of Marjoram-extracted bio-actives in the matrix network designed with the ternary technique demonstrated that the increase in the extract concentration up to 3% can increase encapsulation efficiency. The encapsulation also caused a more cohesive network by better bonding between functional groups in herbal biomolecules and polymer chains of the matrix. Mass transport mechanisms and release kinetics of matrix-encapsulated bio-actives indicated a deviation from Fickian diffusion and the release by diffusion and swelling process. Biologically, matrix-loaded herbal carbohydrate(Epi-alpha-Cadinol) improved fibroblast adhesion and distribution on the substrate surface, and led to the better synthesis of collagen fibers, especially in 3% herbal extract, and antibacterial activities owing to the controlled release of sesquiterpenoids and N-Acetyl-l-proline.

Surface Decontamination of Titanium Dental Implants Subjected to Implantoplasty by Treatment with Citric Acid Solutions

Implantoplasty is one of the most common techniques to remove peri-implantitis from the surface of dental implants. It is a process of mechanization of the titanium surface, causing the loss of the roughness of the dental implant, which leads to difficulty in tissue regeneration. The aim of this research is to apply a decontaminant based on citric acid and add collagen and magnesium cations to promote tissue formation and have a bactericidal character. Eighty commercially pure grade 3 titanium discs were used to perform the implantoplasty protocol, like the one used in dental clinics. They were treated with four different solutions: 25% citric acid, 25% citric acid with the addition of collagen 0.25 g/L, 25% citric acid with the addition of 0.50 g/L and the latter with the addition of 1% Mg (NO3)2. The roughness was determined by confocal microscopy, the contact angle, adhesion and proliferation of HFFs fibroblasts, proliferation of SaOS-2 osteoblasts and bactericidal behavior by culturing very common bacteria in the oral cavity, Gram-positive Streptococcus sanguinis and gordonii and as Gram-negative Pseudomonas aeruginosa. The results showed that the treatment with citric acid slightly increases the roughness and decreases the contact angle from 78 to 13°, making the surface superhydrophilic. Fibroblast proliferation studies show a very significant increase at 24 h, the most favorable solution being the one containing 0.50 g/L of collagen with the presence of magnesium in a 25% citric acid solution. This same solution shows the highest cytocompatibility and osteoblastic proliferation with statistically significant differences with respect to the control and the rest of the solutions. Microbiological studies show a bactericidal effect due to the presence of citric acid, which is especially effective on Gram-positive bacteria. The results allow us to have mouthwashes that can be applied in the patient’s mouth, which will help the regeneration of tissues and avoid new bacterial colonization.

Engineering an Extracellular Matrix Mimic Using Hemoglobin Protein Nanofibrils.

Extracellular matrix (ECM) is essential for tissue development, providing structural support and a microenvironment that is necessary for cells. As tissue engineering advances, there is a growing demand for ECM mimics. Polycaprolactone (PCL) is a commonly used synthetic polymer for ECM mimic materials. However, its biologically inactive surface limits its direct application in tissue engineering. Our study aimed to improve the biocompatibility of PCL by incorporating hemoglobin nanofibrils (HbFs) into PCL using an electrospinning technique. HbFs were formed from bovine hemoglobin (Hb) extracted from industrial byproducts and designed to offer PCL an improved cell adhesion property. The fabricated HbFs@PCL electrospun scaffold exhibits improved fibroblast adherence, proliferation, and deeper fibroblast infiltration into the scaffold compared with the pure PCL scaffold, indicating its potential to be an ECM mimic. This study represents the pioneering utilization of Hb-sourced nanofibrils in the electrospun PCL scaffolds for tissue engineering applications.

Construction of a Curcumin‐Loaded PLLA/PCL Micro‐Nano Conjugated Fibrous Membrane to Synergistically Prevent Postoperative Adhesion From Multiple Perspectives

AbstractPostoperative adhesion (POA) has emerged as a prevalent clinical challenge in soft tissue repair, emphasizing the critical need for preventive measures. However, the complex POA development process makes POA prevention from a single aspect insufficient. Hence, a curcumin‐loaded poly‐L‐lactic acid‐poly (caprolactone) micro‐nano conjugated fibrous membrane (PAPC MCFM (cur)) is engineered to synergistically prevent POA from multiple perspectives, in which poly (caprolactone) (PCL) nanofibers (118 ± 12 nm) with low orientation traverse the oriented poly‐L‐lactic acid (PLLA) microfibers (2.0 ± 0.3 µm). The PAPC MCFM not only significantly improves the mechanical properties of the anisotropic fibrous membrane (AIFM) that the modulus of elasticity and the tensile strength in the direction vertical to microfiber orientation increase by 4.5 and 13.0 times, respectively, but also can further enhance the “contact guidance effect” of AIFM, i.e., hindering fibroblast adhesion, proliferation, and differentiation to myofibroblast through inhibiting integrin β1 activation, vinculin expression and focal adhesion (FA) formation, and the nuclear localization activation of yes‐associated protein (YAP). Except for these effects, PAPC MCFM loading with 2.5 mg mL−1 curcumin can further prevent POA by delivering anti‐inflammatory, antioxidant, and antibacterial properties, and by suppressing fibrosis through decreased transforming growth factor‐β1(TGF‐β1) expression, showing effective POA prevention in rat abdominal cavity and rabbit dura mater models.

Substrates with Tunable Hydrophobicity for Optimal Cell Adhesion.

Electrospinning is a technique used to create nano/micro-fibrous materials from various polymers for biomedical uses. Polymers like polycaprolactone (PCL) are commonly used, but their hydrophobic properties can limit their applications. To enhance hydrophilicity, nonionic surfactants such as sorbitane monooleate (Span80) and poloxamer (P188) can be added to the PCL electrospinning solution without altering its net charge density. These additions enable the successful production of PCL/P188 and PCL/Span80 fibrous substrates. In this study, P188 and Span80 are incorporated into the PCL solutions; they are successfully electrospun into PCL/P188 and PCL/Span80 substrates, respectively. PCL/P188 substrates show that until a specific P188 concentration, fiber and pore sizes are similar to PCL substrates. However, exceeding 0.30% P188 concentration enlarges fibers, impacting fiber uniformity at higher concentrations. Conversely, higher concentrations of Span80 result in thicker, less uniform fibers, indicating potential disruptions in the electrospinning process. Notably, both surfactants significantly improve substrate hydrophilicity, enhancing the adhesion and proliferation of fibroblasts, endothelial cells, and smooth muscle cells. P188, in particular, shows superior efficacy in promoting cell adhesion and growth at concentrations optimized for different cell types. Therefore, precise surfactant concentrations in the electrospinning solution can lead to the optimization of electrospun substrates for tissue engineering applications.