Gelatin nanofiber-reinforced alginate gel scaffolds for corneal tissue engineering

Nonwoven Reinforced Photocurable Poly(glycerol sebacate)-Based Hydrogels

Implantable hydrogels should ideally possess mechanical properties matched to the surrounding tissues to enable adequate mechanical function while regeneration occurs. This can be challenging, especially when degradable systems with a high water content and hydrolysable chemical bonds are required in anatomical sites under constant mechanical stimulation, e.g., a foot ulcer cavity. In these circumstances, the design of hydrogel composites is a promising strategy for providing controlled structural features and macroscopic properties over time. To explore this strategy, the synthesis of a new photocurable elastomeric polymer, poly(glycerol-co-sebacic acid-co-lactic acid-co-polyethylene glycol) acrylate (PGSLPA), is investigated, along with its processing into UV-cured hydrogels, electrospun nonwovens and fibre-reinforced variants, without the need for a high temperature curing step or the use of hazardous solvents. The mechanical properties of bioresorbable PGSLPA hydrogels were studied with and without electrospun nonwoven reinforcement and with varied layered configurations, aiming to determine the effects of the microstructure on the bulk compressive strength and elasticity. The nonwoven reinforced PGSLPA hydrogels exhibited a 60% increase in compressive strength and an 80% increase in elastic moduli compared to the fibre-free PGSLPA samples. The mechanical properties of the fibre-reinforced hydrogels could also be modulated by altering the layering arrangement of the nonwoven and hydrogel phase. The nanofibre-reinforced PGSLPA hydrogels also exhibited good elastic recovery, as evidenced by the hysteresis in compression fatigue stress-strain evaluations showing a return to the original dimensions.

Fabrication of novel nanofiber composed of gelatin/alginate with zirconium oxide NPs regulate orthodontic progression of cartilage degeneration on Wnt/β-catenin signaling axis in MC3T3-E1 cells

Natural macromolecules like alginate and gelatin are employed to create medication delivery systems that are both safe and effective. Zirconium nanoparticles (ZrO2 NPs) have been proposed as a means of enhancing the alginate-gelatin hydrogel's physical and biological properties. This study combines the synthesis of the biopolymers gelatin and alginate nanofibers with nanoparticles of zirconium oxide (GA/NF- ZrO2 NPs). UV, XRD, FTIR, and SEM were used to characterize the synthesized nanofibers. The expression of osteogenic genes was analyzed by western blotting and qualitative real-time polymerase chain reaction (qRT-PCR). Based on our findings, MC3T3-E1 cells are performed for cell viability, apoptosis and reactive oxygen species production by GA/NF- ZrO2 NPs through the Wnt/β-catenin signaling pathway. Cell migration was accelerated at 75 μg/mL concentration after 24 h of damage in a scratch wound healing assay. Proliferation of the MC3T3-E1 cell line was also detected. GA/NF-ZrO2 NPs influenced the osteogenic variation of MC3T3-E1 cells by inducing autophagy. Furthermore, the impact of obstruction on the temporomandibular joint (TMJ) is a subject of ongoing discussion and analysis within the context of animal models. Coordinated GA/NF-ZrO2 NPs on biomaterial nanofibers could be used to introduce physical signals for modifying MC3T3-E1 responds for orthodontic engineering constructs.

Fiber-reinforced scaffolds in soft tissue engineering

Soft tissue engineering has been developed as a new strategy for repairing damaged or diseased soft tissues and organs to overcome the limitations of current therapies. Since most of soft tissues in the human body are usually supported by collagen fibers to form a three-dimensional microstructure, fiber-reinforced scaffolds have the advantage to mimic the structure, mechanical and biological environment of natural soft tissues, which benefits for their regeneration and remodeling. This article reviews and discusses the latest research advances on design and manufacture of novel fiber-reinforced scaffolds for soft tissue repair and how fiber addition affects their structural characteristics, mechanical strength and biological activities in vitro and in vivo. In general, the concept of fiber-reinforced scaffolds with adjustable microstructures, mechanical properties and degradation rates can provide an effective platform and promising method for developing satisfactory biomechanically functional implantations for soft tissue engineering or regenerative medicine.

Interaction of human plasma proteins with thin gelatin-based hydrogel films: a QCM-D and ToF-SIMS study

In the fields of surgery and regenerative medicine, it is crucial to understand the interactions of proteins with the biomaterials used as implants. Protein adsorption directly influences cell-material interactions in vivo and, as a result, regulates, for example, cell adhesion on the surface of the implant. Therefore, the development of suitable analytical techniques together with well-defined model systems allowing for the detection, characterization, and quantification of protein adsorbates is essential. In this study, a protocol for the deposition of highly stable, thin gelatin-based films on various substrates has been developed. The hydrogel films were characterized morphologically and chemically. Due to the obtained low thickness of the hydrogel layer, this setup allowed for a quantitative study on the interaction of human proteins (albumin and fibrinogen) with the hydrogel by Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D). This technique enables the determination of adsorbant mass and changes in the shear modulus of the hydrogel layer upon adsorption of human proteins. Furthermore, Secondary Ion Mass Spectrometry and principal component analysis was applied to monitor the changed composition of the topmost adsorbate layer. This approach opens interesting perspectives for a sensitive screening of viscoelastic biomaterials that could be used for regenerative medicine.

Gelatin-Based Materials in Ocular Tissue Engineering

Gelatin has been used for many years in pharmaceutical formulation, cell culture and tissue engineering on account of its excellent biocompatibility, ease of processing and availability at low cost. Over the last decade gelatin has been extensively evaluated for numerous ocular applications serving as cell-sheet carriers, bio-adhesives and bio-artificial grafts. These different applications naturally have diverse physical, chemical and biological requirements and this has prompted research into the modification of gelatin and its derivatives. The crosslinking of gelatin alone or in combination with natural or synthetic biopolymers has produced a variety of scaffolds that could be suitable for ocular applications. This review focuses on methods to crosslink gelatin-based materials and how the resulting materials have been applied in ocular tissue engineering. Critical discussion of recent innovations in tissue engineering and regenerative medicine will highlight future opportunities for gelatin-based materials in ophthalmology.