Staff

Abstract:
One of the main limitations of biopolymers compared to petroleum-based polymers is their weak mechanical and physical properties. Recent improvements focused on surmounting these constraints by integrating nanoparticles into biopolymer films to improve their efficacy. This study aimed to improve the properties of gelatin–chitosan-based biopolymer layers using zinc oxide (ZnO) and graphene oxide (GO) nanoparticles combined with spermidine to enhance their mechanical, physical, and thermal properties. The results show that adding ZnO and GO nanoparticles increased the tensile strength of the layers from 9.203 MPa to 17.787 MPa in films containing graphene oxide and zinc oxide, although the elongation at break decreased. The incorporation of nanoparticles reduced the water vapor permeability from 0.164 to 0.149 (g.m−2.24 h−1). Moreover, the transparency of the layers ranged from 72.67% to 86.17%, decreasing with higher nanoparticle concentrations. The use of nanoparticles enhanced the light-blocking characteristics of the films, making them appropriate for the preservation of light-sensitive food items. The thermal properties improved with an increase in the melting temperature (Tm) up to 115.5 °C and enhanced the thermal stability in the nanoparticle-containing samples. FTIR analysis confirmed the successful integration of all components within the films. In general, the combination of gelatin and chitosan, along with ZnO, GO, and spermidine, significantly enhanced the properties of the layers, making them stronger and more suitable for biodegradable packaging applications.

Keywords:
nanocomposite,gelatin,chitosan,zinc oxide,graphene oxide

Abstract:
Nicotinamide mononucleotide (NMN) is a promising therapeutic compound limited by instability and poor delivery control. This study introduces a novel approach by developing NMN-loaded liposomes and transethosomes coated with poly(vinyl alcohol) (PVA) to achieve stable, pH-responsive transdermal delivery, significantly improving bioavailability for clinical applications. Unlike conventional uncoated systems, PVA coating adjusted zeta potentials toward less negative values, enhancing colloidal stability, with liposomes shifting from −19 ± 0.73 mV to −15.6 ± 0.40 mV and transethosomes from −22.3 ± 0.84 to −17.72 ± 0.60 mV, and increases entrapment efficiency (e.g., transethosomes from 68.8% to 71.2%) while maintaining particle uniformity (polydispersity index reduced, e.g., from 0.421 to 0.342). FTIR and differential scanning calorimetry analyses confirmed the structural integrity and thermal stability. Ex-vivo studies demonstrated that PVA-coated formulations uniquely provide delayed, pH-dependent NMN release, contrasting with the rapid release of uncoated transethosomes at physiological pH, with reduced diffusion at pH 5.5 for targeted delivery. This innovative use of PVA-coated nanocarriers offers a transformative platform for controlled drug delivery, addressing critical NMN administration challenges.transdermal delivery, nanocarriers, liposome, transethosome, entrapment efficiency, stability

Keywords:
transdermal delivery, nanocarriers, liposome, transethosome, entrapment efficiency, stability