In this study, porous scaffold materials based on polyvinyl alcohol (PVA) and gelatin (Gel) were successfully fabricated and characterized. The mechanism of the reaction, morphology, and crystallinity were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In addition, thermogravimetric analysis (TGA) was performed together with differential scanning calorimetry (DSC) for examining the thermostability and phase transformation of the scaffolds. Degradation and swelling studies of PVA/Gel composite scaffold materials were performed in phosphate-buffered saline. Finally, the mechanical performances had been determined. According to the results, the polymer matrix that was formed by the combination of PVA and gelatin had better thermal stability. The synthesized composite scaffold was amorphous in nature. The addition of gelatin did not affect the fishbone-like microstructure of PVA, which ensures the excellent mechanical properties of the PVA scaffold. The denaturation temperature and elastic modulus of the PVA scaffold were improved by the gelatin addition, but the physical and chemical properties of the PVA scaffold were weakened when the gelatin content exceeded 10%. In addition, the PVA-10G sample has suitable degradability. Therefore, the PVA/Gel composite scaffold might potentially be applied in the field of tissue engineering that demands high strength.
The hydrogels based on gelatin cross-linked with chitosan (CS) and polyvinyl pyrrolidone (PVP) were synthesized using microwave and ultrasonic coupling technique in this study. This interpenetrating polymer network (IPN) hydrogels were cross-linked by glutaraldehyde and 1,2-Epoxy-4-vinylcyclohexane. The presence of function groups in the structure of hydrogel films were confirmed using Fourier transform infrared spectroscopy (FT-IR), thermal stability was measured by DSC, and the swelling behaviors were measured gravimetrically in distilled water at the temperature of 27°C. At last, the mechanical properties were tested. The results showed that the hydrogel prepared with microwave and ultrasonic exhibited the highest tensile strength (86.68MPa), comparing with the hydrogel prepared with traditional method and only microwave reactive field. The FT-IR and XRD results showed that the chemical reactions occurred between the NH2 of chitosan and the COOH of gelatin, and the introduction of ultrasound can improve the reaction rate. The hydrogel film gained in microwave and ultrasonic coupling field has the best combination properties. Therefore, the new microwave-ultrasonic coupling technique is the potential technology to prepare the new hydrogel due to less synthesis time.
A novel composite edible film was synthesized by grafting gelatin chain onto hydroxypropyl methyl cellulose (HPMC) in the presence of glycerol (used as a plasticizer) using a solution polymerization technique. The reaction was carried out in homogeneous aqueous medium. Thermal properties, chemical structure, crystallinity, surface morphology, and mechanical and hydrophilic performance changes of HPMC caused by the addition of gelatin were investigated by differential scanning calorimetry, thermogravimetric, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, universal testing machine and water contact angle. The results shows that HPMC and gelatin are miscible and the hydrophobic property of the blending film can be enhanced with the introduction of the gelatin. Moreover, the HPMC/gelatin blend films are flexible, and exhibit excellent compatibility, good mechanical properties and also thermal stability, and could be promising candidates for food packaging materials.
Collagen (Col) hydrogels are an important biomaterial with many applications in the biomedical sector. However, deficiencies, including insufficient mechanical properties and a rapid rate of biodegradation, hamper their application. In this work, nanocomposite hydrogels were prepared by combining a cellulose nanocrystal (CNC) with Col without any chemical modification. The high-pressure, homogenized CNC matrix acts as nuclei in the collagen’s self-aggregation process. The obtained CNC/Col hydrogels were characterized in terms of their morphology, mechanical and thermal properties and structure by SEM, rotational rheometer, DSC and FTIR, respectively. Ultraviolet-visible spectroscopy was used to characterize the self-assembling phase behavior of the CNC/Col hydrogels. The results showed an accelerated assembling rate with the increasing loading of CNC. The triple-helix structure of the collagen was preserved with a dosage of CNC of up to 15 wt%. The CNC/Col hydrogels demonstrated an improvement in both the storage modulus and thermal stability which is attributed to the interaction between the CNC and collagen by the hydrogen bonds.
Cellulose nanofibers (CNFs) are highly promising nanocarrier materials, boasting excellent drug adsorption and loading potential due to their tunable hydrophilic/lipophilic interfaces. This study is the first to report the successful synthesis of maleic anhydride-modified CNFs (MA-CNFs) via the esterification of CNFs using a solvent-free molten maleic anhydride (MA) system, and it systematically evaluates MACNFs’ dual adsorption performance for water-soluble and lipophilic drugs. A new characteristic peak at 1723 cm−1 in FT-IR confirms the formation of ester bonds, proving the successful grafting of MA onto CNFs. XRD analysis shows that the crystallinity slightly increases from 72.56% to 74.06%, indicating the reaction mainly occurs in the amorphous region. After modification, the material’s hydrophobicity is significantly enhanced (water contact angle: ~63.3° for CNFs vs. ~74.9° for MA-CNFs), and its BET specific surface area rises sharply from 5.03 to 26.29 m2/g. These structural advantages collectively enable MA-CNFs to have adsorption capacities for folic acid (FA, water-soluble) and vitamin E acetate (VEA, lipophilic) that are 1.15 and 2.04 times those of CNFs, respectively. The results demonstrate MA-CNFs are high-performance functional materials fabricated via a green method, with good biocompatibility.