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In this work, the effects of carbon nanofiber (CNF) dispersed poly-ε-caprolactone (PCL) nanocomposite coatings and biomolecules functionalization on silk fibroin based conducting braided nerve conduits were studied for enhancing Neuro 2a cellular activities. A unique combination of biomolecules (UCM) and varying concentrations of CNF (5, 7.5, 10% w/w) were dispersed in 10% (w/v) PCL solution for coating on degummed silk threads. The coated silk threads were braided to develop the scaffold structure. As the concentration of CNF increased in the coating, the electrical impedance decreased up to 400 Ω indicating better conductivity. The tensile and dynamic mechanical property analysis showed better mechanical properties in CNF coated samples. In vitro cytocompatibility analysis proved the non-toxicity of the developed braided conduits. Cell attachment, growth and proliferation were significantly enhanced on the biomolecule functionalized nanocomposite coated silk braided structure, exhibiting their potential for peripheral nerve regeneration and recovery., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Biodegradable polyurethanes offer advantages in the design of injectable or preformed scaffolds for tissue engineering and other medical implant applications. We have developed two-part injectable prepolymer systems (prepolymer A and B) consisting of lactic acid and glycolic acid based polyester star polyols, pentaerythritol (PE) and ethyl lysine diisocyanate (ELDI). This study reports on the formulation and properties of a series of cross linked polyurethanes specifically developed for orthopaedic applications. Prepolymer A was based on PE and ELDI. Polyester polyols (prepolymer B) were based on PE and dl-lactic acid (PEDLLA) or PE and glycolic acid (PEGA) with molecular weights 456 and 453, respectively. Several cross linked porous and non-porous polyurethanes were prepared by mixing and curing prepolymers A and B and their mechanical and thermal properties, in vitro (PBS/37 degrees C/pH 7.4) and in vivo (sheep bi-lateral) degradation evaluated. The effect of incorporating beta-tricalcium phosphate (beta-TCP, 5 microns, 10 wt.%) was also investigated. The cured polymers exhibited high compressive strength (100-190 MPa) and modulus (1600-2300 MPa). beta-TCP improved mechanical properties in PEDLLA based polyurethanes and retarded the onset of in vitro and in vivo degradation. Sheep study results demonstrated that the polymers in both injectable and precured forms did not cause any surgical difficulties or any adverse tissue response. Evidence of new bone growth and the gradual degradation of the polymers were observed with increased implant time up to 6 months.

The advent of injectable polymer technologies has increased the prospect of developing novel, minimally invasive arthroscopic techniques to treat a wide variety of ailments. In this study, we have synthesised and evaluated a novel polyurethane-based injectable, in situ curable, polymer platform to determine its potential uses as a tissue engineered implant. Films of the polymers were prepared by reacting two pentaerythritol-based prepolymers, and characterised for mechanical and surface properties, and cytocompatibility. This polymer platform displayed mechanical strength and elasticity superior to many injectable bone cements and grafts. Cytotoxicity tests using primary human osteoblasts, revealed positive cell viability and increased proliferation over a period of 7 days in culture. This favourable cell environment was attributed to the hydrophilic nature of the films, as assessed by dynamic contact angle (DCA) analysis of the sample surfaces. The incorporation of beta-TCP was shown to improve mechanical properties, surface wettability, and cell viability and proliferation, compared to the other sample types. SEM/EDX analysis of these surfaces also revealed physicochemical surface heterogeneity in the presence of beta-TCP. Based on preliminary mechanical analysis and cytotoxicity results, these injectable polymers may have a number or potential orthopaedic applications; ranging from bone glues to scaffolds for bone regeneration.

Silk fibroin (SF), a natural protein derived from silkworms, has emerged as a promising biomaterial due to its biocompatibility, biodegradability, degradation rate, and tunable mechanical properties. This review delves into the intrinsic attributes of SF that make it an attractive candidate for scaffold development in tissue engineering and regenerative medicine. The distinctiveness of this comprehensive review resides in its detailed exploration of recent advancements in the fabrication techniques of SF‐based fibrous scaffolds, namely electrospinning, freeze‐drying, and 3D printing. An in‐depth analysis of these fabrication techniques is conducted to illustrate their versatility in customizing essential scaffold characteristics, such as porosity, fiber diameter, and mechanical strength. The article meticulously discusses process parameters, advantages, and challenges of each fabrication technique, highlighting the innovative advancements made in the respective field. Furthermore, the review goes beyond fabrication techniques to provide an overview of the latest biomedical applications and research endeavors utilizing SF‐derived scaffolds. From nerve regeneration and wound healing to drug delivery, bone regeneration, and vascular tissue engineering, the diverse applications underscore the versatility of SF in adopting various biomedical challenges. Finally, the article emphasizes the need for standardized characterization techniques, scalable manufacturing processes, and long‐term in vivo studies. [ABSTRACT FROM AUTHOR]

In this work, the effects of carbon nanofiber (CNF) dispersed poly-ε-caprolactone (PCL) nanocomposite coatings and biomolecules functionalization on silk fibroin based conducting braided nerve conduits were studied for enhancing Neuro 2a cellular activities. A unique combination of biomolecules (UCM) and varying concentrations of CNF (5, 7.5, 10% w/w) were dispersed in 10% (w/v) PCL solution for coating on degummed silk threads. The coated silk threads were braided to develop the scaffold structure. As the concentration of CNF increased in the coating, the electrical impedance decreased up to 400 Ω indicating better conductivity. The tensile and dynamic mechanical property analysis showed better mechanical properties in CNF coated samples. In vitro cytocompatibility analysis proved the non-toxicity of the developed braided conduits. Cell attachment, growth and proliferation were significantly enhanced on the biomolecule functionalized nanocomposite coated silk braided structure, exhibiting their potential for peripheral nerve regeneration and recovery. Unlabelled Image • The effect of biomolecule functionalized nanocomposite coating on silk fibroin based braided nerve conduits was studied for enhancing Neuro 2a cellular activities. • This is the first study on Silk- poly-ε-caprolactone–carbon nanofiber braided 3D constructs for bridging damaged nerve gaps. • Slow degradation and non-toxicity of degradation products were confirmed. • The combined effect of unique combination of biomolecules and carbon nanofiber on cell proliferation ended up with an advanced nerve conduit compared to pure silk. • Physical characterization and cell culture studies proved the potential of such nanocomposite coated functionalized braided scaffolds for nerve regeneration. [ABSTRACT FROM AUTHOR]