Basiliximab

Pereskia aculeata Miller (OPN) is a cactus species whose mucilage (MOPN) is rich in arabinogalactan, giving it great technological potential for the encapsulation of different compounds. This study aimed to synthesize microparticles of MOPN and sodium alginate (ALG) for the encapsulation of Lactobacillus acidophilus. The microparticles, produced by ionic gelation, were then coated with whey protein concentrate (WPC), or chitosan (CHI), or left uncoated (UC). Samples were characterized based on morphology, size, chemical structure, thermal properties, and performance under simulated digestion. The microparticles were porous and spherical, with average diameters ranging from 172.50 to 272.25 μm and encapsulation efficiency ranging from 74.73 % to 99.56 %. UC_p microparticles produced with 0.6 % (w/w) MOPN and 0.9 % (w/w) ALG protected the probiotics against the extreme pH levels and digestive enzymes in the gastrointestinal tract, achieving a survival rate of 68.65 %. Coating with WPC (5.25 % w/w) did not improve microbial protection. The survival rate of the probiotic with WPC was 67.45 % and statistically equal to the value found for UC_p microparticles Coating with CHI (1.2 % w/w) significantly reduced the survival rate to 63.27 %, likely due to increased porosity, lower microparticle stability, and the antimicrobial activity of chitosan. In comparison, the survival rate of free (unencapsulated) microorganisms was 56.58 %. These results indicate that the microparticles provided greater protection to L. acidophilus, suggesting that MOPN, in combination with other biopolymers, is an effective material for microbial encapsulation.

Metal-organic framework (MOF) structures containing different metal ions and 1,3,5-trimesic acid (BTC) were fabricated, as the carriers to immobilize chitinase (Chi) for improving the performance of Chi, for the first time. It was found that the immobilization of Chi on Ca-BTC, Ba-BTC, and Ni-BTC increased its activity. Notably, the specific activity of Chi@Ca-BTC was enhanced by 2.1 times that of free Chi, reaching 16.27 U/mg. The catalytic efficiency and substrate affinity of Chi@Ca-BTC were also remarkably improved, confirmed by the k_cat/K_m enhancement (4.2 times) and K_m value reduction (40 %). Moreover, the half-life of Chi@Ca-BTC at the optimum pH 6.0 and 55 °C was prolonged from 1.8 h to 6.8 h. More than 80 % of enzyme activity was retained after 22 cycles of usage, showing superior reusability. It was proved that Ca²⁺ on MOF surface enhanced the formation of hydrogen bonds between the catalytic key amino acid Glu-405 and substrate, accelerating the enzymatic catalysis. Then, Chi@Ca-BTC was employed as an outstanding biocatalytic platform for the degradation of chitin, with 8.1 times increase in conversion efficiency. Such a MOF-based immobilization strategy for improving enzymatic performance is of considerable reference value in designing advanced immobilized enzyme for various polysaccharide biocatalytic reaction.