Design of poly-l-glutamic acid embedded mesoporous bioactive glass nanospheres for pH-stimulated chemotherapeutic drug delivery and antibacterial susceptibility.

In this research, a core-shell type pH-responsive poly-l-glutamic acid embedded mesoporous bioactive glass nanospheres (MBAG/PLGA) was designed via aminosilane functionalization of MBAG using 3-aminopropyltriethoxysilane (APTES). The formation of MBAG/PLGA was well dispersed in an aqueous medium and demonstrated high drug loading efficacy and enhanced drug delivery rate. Daunomycin (DAN) was considered as a model chemotherapeutic drug for loading and release study. The cumulative in vitro release of DAN from DAN loaded MBAG/PLGA (MBAG/PLGA@DAN) was observed to be pH-dependent and, the DAN release rate was much higher at pH ∼ 5.5 compared to pH at 7.4. The modified Kirby-Bauer microbial assay results showed that the MBAG is a potential antimicrobial agent and susceptibility for Gram-negative bacteria is observed to be much higher than Gram-positive ones. Advanced characterization studies such as SEM coupled with EDX, HRTEM, FTIR, XPS, TGA, XRD, and BET analysis were performed to support the findings of this research. Overall, these results demonstrated that MBAG/PLGA is a promising candidate for a pH-responsive localized drug delivery system in bioconjugate science.

Exploration of Wedelia chinensis leaf-assisted silver nanoparticles for antioxidant, antibacterial and in vitro cytotoxic applications.

Green synthetic route of silver nanoparticles (AgNPs) has already been proved to be an advantageous over other physico-chemical approaches due to its simplicity, cost effectiveness, ecofriendly and nontoxicity. In this finding, aqueous Wedelia chinensis leaf extract (WLE) mediated synthesis of AgNPs was approached. Surface plasmon resonance (SPR) band at 408 nm preliminary indicated the formation of AgNPs, while TEM and XRD characterization confirmed the formation of spherically shaped and crystalline AgNPs with an average size of 31.68 nm, respectively. The plausible biomolecules in the aqueous leaf extract responsible for the reduction and stabilization of AgNPs were identified by FTIR analysis and found to be polyphenolic groups in flavonoid. Further, synthesized AgNPs was explored for different biological applications. Biosynthesized AgNPs showed significant free radical scavenging activity as compared to Wedelia leaf extract and antibacterial activity against clinically isolated test pathogens where Gram-negative bacteria were found more susceptible to AgNPs than Gram-positive one. In addition, in vitro cytotoxic response was also evaluated on hepatocellular carcinoma Hep G2 cell lines and showed a dose-dependent cytotoxic response with an IC50 value of 25 µg/mL.

An approach to low-density polyethylene biodegradation by Bacillus amyloliquefaciens.

Low-density polyethylene (LDPE) is a major cause of persistent and long-term environmental pollution. In this paper, two bacterial isolates Bacillus amyloliquefaciens (BSM-1) and Bacillus amyloliquefaciens (BSM-2) were isolated from municipal solid soil and used for polymer degradation studies. The microbial degradation LDPE was analyzed by dry weight reduction of LDPE film, change in pH of culture media, CO2 estimation, scanning electron microscopy (SEM), and fourier transform infrared FTIR spectroscopy of the film surface. SEM analysis revealed that both the strains were exhibiting adherence and growth with LDPE which used as a sole carbon source while FTIR images showed various surface chemical changes after 60 days of incubation. Bacterial isolates showed the depolymerization of biodegraded products in the extracellular media indicating the biodegradation process. BSM-2 exhibited better degradation than BSM-1 which proves the potentiality of these strains to degrade LDPE films in a short span of time.