Proliferation Of L929 Fibroblasts Research Articles

Fabrication of thymol-loaded isabgol/Konjac glucomannan-based microporous scaffolds with enriched antioxidant and antibacterial properties for skin tissue engineering applications.

An antioxidant, antibacterial, and biocompatible biomaterial is essential to repair skin wounds effectively. Here, we have employed two natural biopolymers, isabgol (ISAB) and konjac glucomannan (KGM), to prepare microporous scaffolds by freezing and lyophilization. The scaffolds are loaded with thymol (THY) to impart potent antioxidant and antibacterial activities. The physicochemical properties of the ISAB + KGM + THY scaffold, like porosity (41.8 ± 2.4%), swelling, and biodegradation, were optimal for tissue regeneration application. Compared to the control, ISAB + KGM + THY scaffolds promote attachment, migration, and proliferation of L929 fibroblasts. The antioxidant activity of the ISAB + KGM + THY scaffold was significantly improved after loading THY. This would protect the tissues from oxidative damage. The antibacterial activity of the ISAB + KGM + THY scaffold was significantly higher than that of the control, which would help prevent bacterial infection. The vascularization ability of the ISAB + KGM scaffold was not altered by incorporating THY in the ISAB + KGM scaffold. Therefore, a strong antioxidant, antibacterial, and biocompatible nature of the ISAB + KGM + THY scaffold could be useful for various biomedical applications.

In Vitro Wound-Healing Potential of Phenolic and Polysaccharide Extracts of Aloe vera Gel.

The present study aimed to conduct a comparative investigation of the biological properties of phenolic and polysaccharide extracts obtained using an ultrasound-assisted technique from Aloe vera gel and their effects on each stage of the wound healing process in in vitro experimental models. HPLC analysis showed that the phenolic extract contained aloin, ferulic, and caffeic acid, as well as quercetin dihydrate, as major compounds. Capillary zone electrophoresis indicated the prevalence of mannose and glucose in the polysaccharide extract. Cell culture testing revealed the anti-inflammatory properties of the phenolic extract at a concentration of 0.25 mg/mL through significant inhibition of pro-inflammatory cytokines-up to 28% TNF-α and 11% IL-8 secretion-in inflamed THP-1-derived macrophages, while a pro-inflammatory effect was observed at 0.5 mg/mL. The phenolic extract induced 18% stimulation of L929 fibroblast proliferation at a concentration of 0.5 mg/mL, enhanced the cell migration rate by 20%, and increased collagen type I synthesis by 18%. Moreover, the phenolic extract exhibited superior antioxidant properties by scavenging free DPPH (IC50 of 2.50 mg/mL) and ABTS (16.47 mM TE/g) radicals, and 46% inhibition of intracellular reactive oxygen species (ROS) production was achieved. The polysaccharide extract demonstrated a greater increase in collagen synthesis up to 25%, as well as antibacterial activity against Staphylococcus aureus with a bacteriostatic effect at 25 mg/mL and a bactericidal one at 50 mg/mL. All these findings indicate that the phenolic extract might be more beneficial in formulations intended for the initial phases of wound healing, such as inflammation and proliferation, while the polysaccharide extract could be more suitable for use during the remodeling stage. Moreover, they might be combined with other biomaterials, acting as efficient dressings with anti-inflammatory, antioxidant, and antibacterial properties for rapid recovery of chronic wounds.

Antibacterial and anti-inflammatory Bi-functional carbon dots hydrogel dressing for robust promotion of wound healing

The abuse of antibiotics leading to bacterial resistance has emerged as a significant impediment to wound healing. Consequently, this study developed antibacterial and anti-inflammatory bi-functional carbon dots (AAB-CDs) as the primary active material for the preparation of hydrogel wound dressings, aiming to promote wound healing. The synthesized AAB-CDs exhibited ultra-small size (2.3 nm), abundant surface functional groups, high Zeta potential (30.9 mV), and excellent biocompatibility. The positively charged AAB-CDs with outstanding antibacterial properties, mitigating the risk of bacterial resistance, while the abundant surface functional groups imparted stable antioxidant performance for sustained wound anti-inflammatory effects. Moreover, in vitro experiments demonstrated that the hydrogel dressings exhibited remarkable antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and significantly promoted the proliferation of L929 fibroblasts. In vivo experiments further substantiated the feasibility of the hydrogel dressings in promoting wound healing and histological analysis revealed the biological mechanisms underlying the promotion of wound healing. In conclusion, AAB-CDs with robust antibacterial and anti-inflammatory properties hold tremendous potential for promoting wound healing, providing practical insights for the biological application of CDs.

Polyacrylonitrile (PAN)/carbon nanotube (CNT) electrospun nanofibers: synthesis, characterization, their biocompatibility for L929 fibroblast cells and molecular docking studies

There has been an important interest in to use of electrospun nanomaterials for tissue engineering applications due to the excellent scaffold-cell interaction provided by high interconnectivity and high porosity by electrospun nanofibers. In this study, Polyacrylonitrile (PAN) and carbon nanotube-inserted PAN (PAN/CNT) nanofibers were produced by the electrospinning method and characterized by SEM, FT-IR, and EIS spectroscopy. Both PAN and PAN/CNT nanofibers were obtained beadless and ordered with the average fiber diameters of 277.61 ± 43.6 and 171.01 ± 48.4, respectively. The influence of CNT addition on PAN nanofibers was observed with the decrease of diameter and increase of electrical conductivity of nanofibers. Then, the biocompatibility of PAN and PAN/CNT nanofibers was evaluated by the MTT and AO/EB double-staining experiments. It was observed that the nanofibers showed no cytotoxic effect on L929 fibroblast cells. In the docking experiments, while both PAN and PAN/CNT showed energetically favorable interactions (ΔG = −4.60 kcal/mol; −7.26 kcal/mol, respectively) with the membrane bilayer complex, PAN/CNT formed a more stable binding with the cellular membrane compared to PAN alone. Docking results mechanistically support the more effective increase in the proliferation of L929 fibroblasts at high concentrations in vitro, as PAN/CNT exhibits stronger binding affinity and interaction with the cellular membrane. The increase in electrical conductivity of nanofibers influenced the proliferation positively, as well.

An antibacterial and healing-promoting collagen fibril constructed by the simultaneous strategy of fibril reconstitution and ε-polylysine anchoring for infected wound repair.

The development of antibacterial dressings has attracted much attention to address the disordered wound healing caused by bacterial infection. Constructing dressings that have desirable antibacterial activity and could promote wound healing is important for infected wound repair. Inspired by the role of the key regulator collagen fibrils with D-periodic functional domains in the physiological wound healing process, we developed an antibacterial and wound healing-promoting collagen fibril with a structure highly similar to natural collagen in ECM and inherent antibacterial activity by the simultaneous strategy of fibril reconstitution and the antibacterial agent ε-polylysine (ε-PL) anchoring. Accompanied by the fibrillogenesis of collagen molecules, the anchorage of ε-PL into collagen fibrils was actualized through the formation of the covalent bond catalyzed by transglutaminase (TGase) between ε-PL and collagen. The collagen fibril possessed natural D-periodicity and achieved 20% ε-PL graft yield by co-assembling collagen/ε-PL mediated by 25 U g-1 TGase, which showed a satisfactory proliferation of L929 fibroblasts and sustained inhibition rates above 90% against E. coli and S. aureus. The rat S. aureus-infected dermal wound model further demonstrated that the reconstituted antibacterial collagen fibril visibly promoted re-epithelialization, new collagen deposition, and angiogenesis by down-regulating the inflammatory-relative gene IL-6 and up-regulating the relative activity factor expression of CD31, achieving accelerated infected wound healing with 61.89% ± 3.96% wound closure on postoperative day 7 and full closure on day 14.

Preparation of an antibacterial dressing for simultaneous delivery of polyhexamethylene biguanide and platelet-rich plasma, and evaluation of the dressing's ability to promote infected skin repair

Slow wound healing caused by bacterial infection is a critical clinical challenge. Moreover, finding common preservatives that fulfill current medical requirements has proved difficult. Therefore, we designed a multifunctional wound dressing based on the hydrogen-bonded assembly of polyvinyl alcohol (PVA)/polyhexamethylene biguanide (PHMB)/platelet-rich plasma (PRP). The hydrogels were prepared by a simple and environmentally friendly procedure by repeated freeze–thaw cycles without a chemical crosslinking agent. Characterization studies revealed the outstanding stability of these composite hydrogels. Bacteriostatic ring experiments revealed that the PHMB-containing hydrogel possessed strong antibacterial effects. The hydrogel with PRP showed low cytotoxicity and significantly stimulated the proliferation of L929 fibroblasts, according to live/dead cell staining and 3-(4,5-dimethylthiazol-2-yl)− 5-(3-carboxymethoxyphenyl)− 2-(4-sulfophenyl)− 2 H-tetrazolium (MTS) testing results. The PVA/PHMB/PRP composite dressing reduced inflammatory response, promoted epithelization, enhanced collagen production and vascular regeneration, and restored skin appendages in vivo. These results indicate that the PVA/PHMB/PRP wound dressing is a promising biological material with synergistic antibacterial and wound-healing functions.

Fabrication and evaluation of multifunctional agarose based electrospun scaffolds for cutaneous wound repairs.

Despite several advances in chronic wound management, natural product based scaffolds with high exude absorption and mechanical strength are still a hotspot in the medical field. Thus, present study illustrates the fabrication ofagarose (AG;10% w/v)/polyvinyl alcohol 12% w/v) based multifunctional nanofibrous electrospun scaffolds. Zinc citrate (1%, 3% and 5% w/w of the polymer) was used as a potential antibacterial agent. The fabricated scaffolds exhibit a swelling of ∼550% in phosphatebuffersaline and mechanical strength of 10.11±0.31MPa which is suitable for most of the wound healing applications that require high strength. In vitro study revealed an increased migration and proliferation of L929 fibroblasts with AGblends when compared to the control. The fabricated scaffolds exhibited antibacterial properties against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacterial strains. Hence, a multifunctional (ability to protect wounds from bacterial infections along with effective swelling and mechanical support), natural product based, eco-friendly scaffold to serve as a potential wound dressing material has been successfully fabricated.

Additive Manufactured Poly(ε-caprolactone)-graphene Scaffolds: Lamellar Crystal Orientation, Mechanical Properties and Biological Performance.

Understanding the mechano–biological coupling mechanisms of biomaterials for tissue engineering is of major importance to assure proper scaffold performance in situ. Therefore, it is of paramount importance to establish correlations between biomaterials, their processing conditions, and their mechanical behaviour, as well as their biological performance. With this work, it was possible to infer a correlation between the addition of graphene nanoparticles (GPN) in a concentration of 0.25, 0.5, and 0.75% (w/w) (GPN0.25, GPN0.5, and GPN0.75, respectively) in three-dimensional poly(ε-caprolactone) (PCL)-based scaffolds, the extrusion-based processing parameters, and the lamellar crystal orientation through small-angle X-ray scattering experiments of extruded samples of PCL and PCL/GPN. Results revealed a significant impact on the scaffold’s mechanical properties to a maximum of 0.5% of GPN content, with a significant improvement in the compressive modulus of 59 MPa to 93 MPa. In vitro cell culture experiments showed the scaffold’s ability to support the adhesion and proliferation of L929 fibroblasts (fold increase of 28, 22, 23, and 13 at day 13 (in relation to day 1) for PCL, GPN0.25, GPN0.5, and GPN0.75, respectively) and bone marrow mesenchymal stem/stromal cells (seven-fold increase for all sample groups at day 21 in relation to day 1). Moreover, the cells maintained high viability, regular morphology, and migration capacity in all the different experimental groups, assuring the potential of PCL/GPN scaffolds for tissue engineering (TE) applications.

Impacts of Blended Bombyx mori Silk Fibroin and Recombinant Spider Silk Fibroin Hydrogels on Cell Growth.

Binary-blended hydrogels fabricated from Bombyx mori silk fibroin (SF) and recombinant spider silk protein eADF4(C16) were developed and investigated concerning gelation and cellular interactions in vitro. With an increasing concentration of eADF4(C16), the gelation time of SF was shortened from typically one week to less than 48 h depending on the blending ratio. The biological tests with primary cells and two cell lines revealed that the cells cannot adhere and preferably formed cell aggregates on eADF4(C16) hydrogels, due to the polyanionic properties of eADF4(C16). Mixing SF in the blends ameliorated the cellular activities, as the proliferation of L929 fibroblasts and SaOS-2 osteoblast-like cells increased with an increase of SF content. The blended SF:eADF4(C16) hydrogels attained the advantages as well as overcame the limitations of each individual material, underlining the utilization of the hydrogels in several biomedical applications.

Palmatine-loaded electrospun poly(ε-caprolactone)/gelatin nanofibrous scaffolds accelerate wound healing and inhibit hypertrophic scar formation in a rabbit ear model.

Hypertrophic scar (HS) has been considered as a great concern for patients and a challenging problem for clinicians as it can cause functional debility, cosmetic disfigurement and psychological trauma. Although many methods have been developed to prevent and treat HS, the scarless healing is still a worldwide medical problem. In this study, palmatine-loaded poly(ε-caprolactone)/gelatin nanofibrous scaffolds (PCL/GE/PALs) were fabricated by electrospinning, and their effects on wound healing and HS formation were investigated. These nanofiber mats exhibit good antibacterial and antioxidant activities. In vitro studies indicate PCL/GE/PAL scaffolds can facilitate the adhesion, spreading and proliferation of L929 fibroblasts. In vivo tests demonstrate the full-thickness wounds treated with PCL/GE/PAL scaffolds heal about 3.5 days earlier than those in the control group. Scar elevation index measurements and histological analyses reveal PCL/GE/PAL scaffolds significantly inhibit HS formation, with the decrease in the thickness of dermis and epidermis, the number of fibroblasts, as well as the density of collagen and microvascular. Accelerating wound healing and inhibiting HS formation of these scaffolds are contributed to the sustained release of palmatine. The present work validates the potential use of palmatine-loaded electrospun nanofibrous scaffold PCL/GE/PALs as a functional wound dressing for healing wounds and preventing HS formation.

Heparin-hyaluronic acid nanofibers for growth factor sequestration in spinal cord repair.

Growth factor (GF) delivery is a common strategy for spinal cord injury repair, however, GF degradation can impede long-term therapies. GF sequestration via heparin is known to protect bioactivity after delivery. We tested two heparin modifications, methacrylated heparin and thiolated heparin, and electrospun these with methacrylated hyaluronic acid (MeHA) to form HepMAHA and HepSHHA nanofibers. For loaded conditions, MeHA, HepMAHA, and HepSHHA fibers were incubated with soluble basic fibroblast growth factor (bFGF) or nerve growth factor (NGF) and rinsed with PBS. Control groups were hydrated in PBS. L929 fibroblast proliferation was analyzed after 24 hr of culture in either growth media or bFGF-supplemented media. Dissociated chick dorsal root ganglia neurites were measured after 3 days of cell culture in serum free media (SFM) or NGF-supplemented SFM (SFM + NGF). In growth media, fibroblast proliferation was significantly increased in loaded HepMAHA (α < .05) compared to other groups. In SFM, loaded HepMAHA had the longest average neurite length compared to all other groups. In SFM + NGF, HepMAHA and HepSHHA had increased neurite lengths compared to MeHA, regardless of loading (α < .01), suggesting active sequestration of soluble NGF. HepMAHA is a promising biomaterial for sequestering released GFs in a spinal cord injury environment and will be combined with GF filled microspheres for future studies.

Pholiota nameko Polysaccharides Promotes Cell Proliferation and Migration and Reduces ROS Content in H2O2-Induced L929 Cells.

Pholiota nameko, a type of edible and medicinal fungus, is currently grown extensively for food and traditional medicine in China and Japan. It possesses various biological activities, such as anti-inflammatory, anti-hyperlipidemia and antitumor activities. However, P. nameko has rarely been discussed in the field of dermatology; identifying its biological activities could be beneficial in development of a new natural ingredient used in wound care. To evaluate its in vitro wound healing activities, the present study assessed the antioxidant and anti-collagenase activities of P. nameko polysaccharides (PNPs) prepared through fractional precipitation (40%, 60% and 80% (v/v)); the assessments were conducted using reducing power, hydroxyl radical scavenging activity, dichloro-dihydro-fluorescein diacetate and collagenase activity assays. The ability of PNPs to facilitate L929 fibroblast cell proliferation and migration was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and scratch assays. The findings indicated that, among all fractions, PNP-80 showed the best antioxidant and anti-collagenase activity, as measured by their reducing power (IC50 of PNP-80 was 2.43 ± 0.17 mg/mL), the hydroxyl radical scavenging (IC50 of PNP-80 was 2.74 ± 0.11 mg/mL) and collagenase activity assay, and significantly reduced cellular ROS content, compared with that of H2O2-induced L929 cells. Moreover, PNP-80 significantly promoted L929 fibroblast proliferation and migration, compared with the control group. Overall, we suggested that PNP-80 could be a promising candidate for further evaluation of its potential application on wound healing.

A novel silkworm pupae carboxymethyl chitosan inhibits mouse L929 fibroblast proliferation

A novel silkworm pupae carboxymethyl chitosan inhibits mouse L929 fibroblast proliferation

Polydopamine-collagen complex to enhance the biocompatibility of polydimethylsiloxane substrates for sustaining long-term culture of L929 fibroblasts and tendon stem cells.

Polydimethylsiloxane (PDMS) is a commercialized polymer extensively used in the fabrication of versatile microfluidic microdevices for studies in cell biology and tissue engineering. However, the inherent surface hydrophobicity of PDMS is not optimal for cell culture and thus restrains its applications for investigation of long-term behaviors of fibroblasts and stem cells. To improve the surface biocompatibility of PDMS, a facile technique was developed by modifying the PDMS surface with polydopamine-collagen (COL/PDA) complex. The successful synthesis of COL/PDA was verified through proton nuclear magnetic resonance spectroscopy. Compared to surface coating solely with COL or PDA, the surface wettability was significantly improved on COL/PDA-modified PDMS substrates based on water contact angle characterizations. The modified PDMS surface remarkably enhanced the initial adhesion and long-term proliferation of L929 fibroblasts and tendon stem cells (TSCs). Additionally, the effects of COL/PDA coating on cell viability and apoptosis were further investigated under prolonged incubation. We found that the COL/PDA coating on PDMS resulted in a substantial increase of cell viability compared to native PDMS, and the cell apoptosis was considerably impeded on the modified PDMS. This study demonstrated that COL/PDA coating can effectively enhance the surface biocompatibility of PDMS as verified by the enhanced adhesion and long-term proliferation of L929 fibroblasts and TSCs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 408-418, 2018.

The effect of ozone gas sterilization on the properties and cell compatibility of electrospun polycaprolactone scaffolds

The growing area of tissue engineering has the potential to alleviate the shortage of tissues and organs for transplantation, and electrospun biomaterial scaffolds are extremely promising devices for translating engineered tissues into a clinical setting. However, to be utilized in this capacity, these medical devices need to be sterile. Traditional methods of sterilization are not always suitable for biomaterials, especially as many commonly used biomedical polymers are sensitive to chemical-, thermal- or radiation-induced damage. Therefore, the objective of this study was to evaluate the suitability of ozone gas for sterilizing electrospun scaffolds of polycaprolactone (PCL), a polymer widely utilized in tissue engineering and regenerative medicine applications, by evaluating if scaffolds composed of either nanofibres or microfibres were differently affected by the sterilization method. The sterility, morphology, mechanical properties, physicochemical properties, and response of cells to nanofibrous and microfibrous PCL scaffolds were assessed after ozone gas sterilization. The sterilization process successfully sterilized the scaffolds and preserved most of their initial attributes, except for mechanical properties. However, although the scaffolds became weaker after sterilization, they were still robust enough to use as tissue engineering scaffolds and this treatment increased the proliferation of L929 fibroblasts while maintaining cell viability, suggesting that ozone gas treatment may be a suitable technique for the sterilization of polymer scaffolds which are significantly damaged by other methods.

Biomimetic Coating of Hydroxyapatite on Glycerol Phosphate-Conjugated Polyurethane via Mineralization.

In this study, glycerol phosphate was introduced into polyurethane (PU) to promote the coating stability of hydroxyapatite (HA) during its mineralization on the PU surface. Glycerol phosphate was successfully conjugated with the PU chain during polymerization. Phosphate groups in glycerol phosphate accelerated the nucleation of HA under calcium phosphate ion-rich conditions (concentrated simulated body fluid), resulting in the enhancement of structural stability. The robust interface between HA and PU also improved mechanical properties. Hydrophilic phosphate groups and bioactive HA improved in vitro cellular responses in terms of the attachment and proliferation of L929 fibroblasts and MC3T3-E1 preosteoblasts. Thus, the highly elastic and bioactive PU-gp-HA could be a promising candidate for tissue engineering applications that experience frequent deformation, including diverse cartilage replacements.

Composite resin reinforced with silver nanoparticles–laden hydroxyapatite nanowires for dental application

ObjectiveThe object is to find a functional one-dimensional nanofibrous filler for composite resin, which is able to provide both efficient reinforcement and high antibacterial activity. MethodsHydroxyapatite (HA) nanowires were synthesized via hydrothermal technique using calcium oleate as the precursor. Polydopamine (PDA)–coated HA (HA–PDA) nanowires were prepared by soaking HA nanowires in dopamine (DA) aqueous solution. Silver nanoparticles (AgNPs)–laden HA (HA–PDA–Ag) nanowires were prepared via reduction reaction by adding silver nitrate and glucose into HA–PDA suspensions in DI water. The resulted HA–PDA–Ag nanowires were then mixed into Bis-GMA/TEGDMA (50/50, w/w) at 4–10wt.%, thermal-cured, and submitted to characterizations including mechanical properties, interfacial adhesion between filler and resin matrix, distribution of HA nanowires and AgNPs, as well as silver ion release, cytotoxicity and antibacterial activity. ResultsHA–PDA–Ag nanowires were readily obtained and the loading amounts of AgNPs could be controlled by adjusting the feeding doses of silver nitrate and HA–PDA nanowires. Benefiting from the PDA surface layer, HA–PDA–Ag nanowires could disperse well in composite resin and form good interfacial adhesion with the resin matrix. In comparison with neat resin, significant increases in flexural strength and modulus of cured composites were achieved at the addition amounts of HA–PDA–Ag nanowires being 6–8wt.%. The distribution of AgNPs was homogeneous throughout the resin matrix in all designs, which endowed the composites with high antibacterial activity against streptococcus mutans. Continuous silver ion release from composites was detected, however, it was determined the composites would have insignificant cytotoxicity based on the proliferation of L929 fibroblasts in extracts of HA–PDA–Ag nanowires. SignificanceThe finding proved that HA–PDA–Ag nanowires could serve as functional nanofillers for composite resins, which should help much in developing materials for satisfactory long-term clinical restorations.

Fabrication and characterization of a novel crosslinked human keratin-alginate sponge.

Human hair keratins have been explored for biomedical applications because of their abundance, bioactivity and processability. However, pure keratin templates have poor mechanical properties, which limit their practical relevance. Herein, we described a novel composite sponge, consisting of human hair keratins chemically crosslinked with alginate using 1-ethyl-3-dimethylaminopropyl carbodiimide hydrochloride, with improved mechanical properties. Fourier transform infrared spectroscopy (FTIR) and free amine group quantification using ninhydrin revealed a maximum crosslinking index of 82.1 ± 1.3%. With increasing alginate proportions, the sponges exhibited increased tensile strength, tensile modulus and compression modulus at maximum values of 10.3 ± 1.92 kPa, 219.07 ± 52.39 kPa and 191.48 ± 32.89 kPa, respectively. The crosslinked sponges also demonstrated water vapour transmission rates comparable to commercial wound dressings. Meanwhile, sponges with higher proportions of keratin showed lower water uptake capacities and higher degradation rates by proteinase K, in comparison with sponges with higher proportions of alginate. Higher proportions of keratin on coated two-dimensional surfaces and in three-dimensional sponges resulted in more attachment and improved proliferation of L929 fibroblasts, verifying the bioactive role of keratin in the composites. In addition, subcutaneous implantation of the keratin-alginate sponges into C57BL/6NTac mice over 4 weeks showed no significant immunological reaction and minimal formation of fibrotic capsules. Furthermore, the sponges supported cellular infiltration, neo-tissue formation and vascularization in vivo. These findings demonstrated the feasibility of producing crosslinked human hair keratin-alginate sponges, with tuneable physical and mechanical properties, which are cell compliant in vitro and biocompatible in vivo, suggesting their potential for clinically relevant exploitations. Copyright © 2016 John Wiley & Sons, Ltd.

An interpenetrating network biohydrogel of gelatin and gellan gum by using a combination of enzymatic and ionic crosslinking approaches

Gelatin is a popular substrate for cell culture applications due to its biocompatibility and biodegradability. However, the mechanical property of gelatin is not satisfactory in certain tissue engineering areas where tunable and higher mechanical strengths are required. To achieve this purpose without exposure of materials to cytotoxic chemicals or procedures, a new biohydrogel of gelatin and gellan gum with an interpenetrating network (IPN) structure was prepared using a combination of enzymatic and ionic crosslinking approaches. The gelation procedure and thermal stability of theIPNstructure were demonstrated in detail by a rheological study. The resultingIPNbiohydrogel exhibited significantly increased and tunable mechanical strength, decreased swelling ratios and lower degradation rate compared with pure gelatin gel. The composite biohydrogels supported the attachment and proliferation ofL929fibroblasts as shownin vitro. These results indicate that this mechanically robust biohydrogel has the promising potential for serving as a cell support in the field of tissue engineering. © 2013 Society of Chemical Industry

Mechanism of inhibition on L929 rat fibroblasts proliferation induced by potential adhesion barrier material poly(p-dioxanone-co-l-phenylalanine) electrospun membranes

Fibroblast plays an important role in the occurrence of postoperative tissue adhesion; materials that have particular "cell-material" interactions to inhibit proliferation of fibroblast will be excellent potential adhesion barriers. In the current study, we synthesized copolymers of p-dioxanone and L-phenylalanine (PDPA) and evaluated the mechanism of its particular inhibition effect on L929 fibroblast proliferation when used as a culture surface. PDPA electrospun membranes could induce apoptosis of L929 fibroblasts. We hypothesized there were two reasons for the apoptosis induction: one was the ability to facilitate cell adhesion of materials, and the other was production of the degradation product, L-phenylalanine. Ninhydrin colorimetric results revealed that L-phenylalanine was continuously released during the culture process and could induce apoptosis in L929 cells. Relatively poor cell adhesion and constant release of L-phenylalanine made PDPA-1 to be the most efficient polymer for the induction of apoptosis. Analysis of apoptosis-related genes revealed that PDPA-induced apoptosis might be performed in a mitochondrial-dependent pathway. But poly(p-dioxanone)-induced apoptosis might occur in a c-Myc independent pathway that was different from PDPA.