PEGylation of poly(hydroxybutyrate) into multicomponent nanostructures and loading thereon with bioactive molecules for potential biomedical applications

Bacterial Polysaccharide-Stabilized Silver Nanoparticles Photocatalytically Decolorize Azo Dyes

Bacterial polysaccharide is advantageous over plant, algal, and fungal polysaccharides in terms of stability, non-toxicity, and biodegradable nature. In addition, bacterial cell wall polysaccharide (CPs) is very little explored compared to exopolysaccharide. In this study, CPs have been isolated from thermotolerant Chryseobacterium geocarposphaerae DD3 (CPs3) from textile industry dye effluent. Structural characterization of the CPs was done by different techniques, viz., scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). CPs3 demonstrated compact non-porous amorphous surface composed of evenly distributed macromolecular lumps. TGA revealed a high thermostability (~ 350 °C) of the polysaccharide. FTIR and NMR confirm the polysaccharidic nature of the polymer, consisting of glucose units linked by both β-(1 → 3) and β-(1 → 4) glycosidic bonds. The functional properties of CPs3 were evaluated for industrial use as additive, especially antibacterial, emulsification, and flocculation capacities. A single-step green synthesis of silver nanoparticle (AgNP) was performed using CPs3. AgNP was characterized using ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), AFM, and particle size analyses. The CPs3-stabilized AgNP exhibited potential photocatalytic activity against a broad range of azo dyes, congo red (88.33 ± 0.48%), methyl red (76.81 ± 1.03%), and malachite green (47.34 ± 0.90%) after only 3 h of reaction. According to our knowledge, this is the first report on CPs from C. geocarposphaerae. The results demonstrated multifunctionality of CPs3 in both prospective, CPs3 as additive in biotechnology industry as well as Cps3-stabilized AgNP for bioremediation of azo dye.

Process intensification of biopolymer polyhydroxybutyrate production by pseudomonas putida SS9: A statistical approach

There are numerous elements of daily life where plastic is employed, yet it is uncertain exactly when it will deteriorate. Poly-(3-hydroxybutyrate) (PHB), a biodegradable polymer, is viewed as a possible substitute for synthetic plastics made from petroleum. With Pseudomonas putida SS9, the current study sought to enhance operational conditions and nutritional factors to enhance PHB production. To maximize the impacts of operational factors, a combination of response surface modeling (RSM) and artificial neural networks (ANN) has been applied. PHB content was used as the response while the interaction effects of the factors were examined. The optimal parameters for PHB synthesis were further tested in a lab scale fermentor. Under optimal conditions, 13.83 g/L of C, 0.57 g/L of N, 0.59 g/L of P, the maximal productivity of PHB obtained with Pseudomonas putida SS9 is 12.89 g/L after 84 h. A mean square value of 15.7 with P < 0.0001 were obtained from the ANOVA results of quadratic polynomial model using RSM. The same construct was employed in MATLAB software to train a feed-forward ANN using the back-propagation approach, generating 12.88 g/L. The data indicated that a properly trained ANN model outperforms the RSM model in prediction. Furthermore, employing dairy waste (cheese whey) as a low-cost feedstock resulted in an equally proportionate PHB yield of 12.02 g/L. Therefore, cheese whey appeared to be a viable alternative carbon source over optimized synthetic media.

Biosynthesis of folic acid appended PHBV modified copper oxide nanorods for pH sensitive drug release in targeted breast cancer therapy

Multifunctional nanoplatforms as nanocarriers have attracted the interest of many scientists because they can achieve greater therapeutic effect in anticancer drug delivery to tumors with potential to improve cancer treatment, while currently available therapies are nonspecific and ineffectual. In present study, notable cancer therapeutic strategy which combines PEG functionalized poly (3-hydroxybutyric acid-co-hydroxyvaleric acid) (PHBV) nanospheres decorated with folic acid for delivery of paclitaxel (PTX) drug conjugated with copper oxide (CuO) nanoparticles (NPs) is proposed. Moreover, PTX loading with CuO NPs in PHBV nanosphere was done to increase its solubility and analyze its apoptotic effects in human breast cancer (MCF-7) cells. The pH-sensitive CuO-PTX@PHBV-PEG-FA nanosystem was successfully developed, as evidenced by number of characterizations. Resultant CuO-PTX@PHBV-PEG-FA NPs were 148.93 ± 10.5 nm in size, having 0.206 PDI, with -20.3 ± 0.6 mV zeta potential. MTT assay in MCF-7 cells was used to assess cell viability, while anticancer potential of CuO-PTX@PHBV-PEG-FA nanosystem was confirmed through different staining techniques. According to invitro studies, FA-conjugated PHBV modified CuO-PTX targeted nanoparticles exhibited higher anticancer effect than free PTX probably due to binding interaction of folate receptor with cells that overexpress the target. This nanosystem has the potential to be a promising breast cancer treatment agent.