DOI: 10.14457/tu.the.2023.474
title: Development of composite hydrogels from hemp-derived cellulose nanofibers for biomedical application

description: Alkaline treatment and bleaching procedure were used to treat hemp before further use, resulting in cellulose nanocrystals (CNCs). For first scope, CNCs were combined with polyvinyl alcohol to produce a composite hydrogel. To crosslink the polyvinyl alcohol and different amount of, sodium tetraborate (borax) was used in combination with a different concentration of CNCs (1,3,5,7, and 10% w/v) of cellulose nanocrystals. In comparison with pure polyvinyl alcohol, no obvious peak shift was seen in the FT-IR spectrum because of the small number of cellulose nanocrystals. Once the water molecules were eliminated, porosity was formed. As the CNCs were integrated into the composite hydrogel system, it was obviously induced the smaller pore sizes. Up to 200 °C, the material continued to be thermally stable. The melting temperature was a bit raised in the presence of CNCs, while the glass transition temperature stayed essentially constant. In order to compare, the swelling test was conducted for 180 minutes, using both deionized water and PBS solution (pH; 7.4) at 37 °C. For swelling ratio (%), It was discovered that adding cellulose nanocrystal into composite hydrogel expanded more than the pure PVA hydrogel, and this observation was related to the composite hydrogel's microstructure outcome. The cytotoxicity was carried out with Hela cells and HDFa cells. The produced hydrogel containing various quantities of cellulose nanocrystals demonstrated a better percentage of cell viability in comparison to the pure PVA hydrogel. The synthesized composite hydrogels made of polyvinyl alcohol and hemp-derived cellulose nanocrystals were shown to be a great option for scaffold in medical applications. For second scope, the injectable composite hydrogel based on thermo-responsive Poly(N-Isopropylacrylamide) (PNIPAAm) and Chitosan (Cs), reinforced with cellulose nanocrystals (CNCs), was successfully developed. The research was estimated the effect of cellulose nanocrystals after integrated to thermo-responsive injectable-based composite hydrogel. The composite hydrogel was created through a photopolymerization. While NIPAAm is known for its thermo-response, it does not possess biocompatibility or biodegradability. In order to improve NIPAAm's biocompatibility and biodegradability for possible use as a biomedical material, chitosan was included in NIPAAm for the matrix phase. It is verified by the FT-IR spectra of each hydrogel component that an effective composite hydrogel based on thermo-responsive PNIPAAm/Cs/CNC injectables was created. Porosity formed as a result of the absence of water molecules. The composite hydrogels shown a reduction in pore size in the CNC-added condition. The addition of CNC contents is dropped in thermal stability. The samples' VPTT ranged from 34 to 38 °C, which is not too far from the body's normal temperature of 37 °C. The samples' injectability was seen in the photograph, which injected the samples on the glass slides at 37 °C. In PBS solution (pH; 7.4), the ESR was examined at three fixed temperatures (25, 37, and 45 °C). It was found that the composite hydrogel with higher cellulose nanocrystal contents had a greater ESR than the condition without CNCs. As non-toxic hydrogels for fibroblast cells (HDFa), which were suggested to be a biomedical material, all circumstances of thermo-responsive injectable composite hydrogels were examined.