Preparation of xyloglucan-grafted poly(N-hydroxyethyl acrylamide) copolymer by free-radical polymerization for in vitro evaluation of human dermal fibroblasts.

Xyloglucan is a rigid polysaccharide that belongs to the carbohydrate family. This hemicellulose compound has been widely used in biomedical research because of its pseudoplastic, mucoadhesive, mucomimetic, and biocompatibility properties. Xyloglucan is a polyose with no amino groups in its structure, which also limits its range of applications. It is still unknown whether grafting hydrophilic monomers onto xyloglucan can produce derivatives that overcome these shortcomings. This work aimed to prepare the first copolymers in which N-hydroxyethyl acrylamide is grafted onto tamarind xyloglucan by free-radical polymerization. The biocompatibility of these structures in vitro was evaluated using human dermal fibroblasts. Gamma radiation-induced graft polymerization was employed as an initiator by varying the radiation dose from 5-25 kGy. The structure of the graft copolymer, Xy-g-poly(N-hydroxyethyl acrylamide), was verified by thermal analysis, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The findings indicate that the degree of grafting and the cytotoxicity/viability of the xyloglucan-based copolymer were independent of dose. Notably, the grafted galactoxyloglucan exhibited efficient support for human dermal fibroblasts, showing heightened proliferative capacity and superior migration capabilities compared to the unmodified polymer. This copolymer might have the potential to be used in skin tissue engineering.

Discovering the effect of solvents on poly(2-aminoethyl methacrylate) grafting onto chitosan for an in vitro skin model.

The design of controlled grafting copolymers is critical in synthesizing effective artificial cellular matrices because of their regulatory role in cellular behavior. However, it is unclear whether poly(2-aminoethyl methacrylate) grafted onto chitosan generated by gamma-radiation-induced graft polymerization in different solvents can influence the physicochemical properties and biotech applicability of the copolymer. This work aims to demonstrate for the first time the effect of various solvents on the synthesis, properties, and biological performance of grafted chitosan using the simultaneous irradiation method. The results proved that the solvent is one of the critical factors affecting the properties of the modified polysaccharide. The degree of grafting showed a solvent-dependent profile. Hexane presented utmost importance concerning the degree of grafting. Ethyl acetate showed the best results in grafting extent and human dermal fibroblast growth. These findings indicate that proper solvent selection determines the possible copolymer use for in vitro engineered skin substitute models.

A poly (saccharide-ester-urethane) scaffold for mammalian cell growth.

Chitosan and poly(3-hydroxybutyrate) are non-toxic, biodegradable, and biocompatible polymers extensively used in regenerative medicine. However, it is unknown whether the chemical combination of these polymers can produce a biomaterial that induces an appropriate cellular response in vitro in mammalian cells. This study aimed to test the ability of a novel salt-leached polyurethane scaffold of chitosan grafted with poly(3-hydroxybutyrate) to support the growth of three mammalian cell lines of different origin: a) HEK-293 cells, b) i28 mouse myoblasts, and c) human dermal fibroblasts. The viability of the cells was assessed by either evaluation of their capacity to maintain the expression of the green fluorescent protein by adenoviral transduction or by esterase activity and plasma membrane integrity. The results indicated that the three cell lines attached well to the scaffold; however, when i28 cells were induced to differentiate, they did not produce morphologically distinct myofibers, and cell growth ceased. In conclusion, the findings reveal that, altogether, these observations suggest that this foam scaffold supports cell growth and proliferation but may not apply to all cell types. Hence, one crucial question yet to be resolved is a poly (saccharide-ester-urethane) derivative with a nano-topography that elicits a similar cellular response for different biological environments.