ABSTRACT
Cationic random copolymers (PCm) consisting of 2-(methacryloyloxy)ethyl phosphorylcholine (MPC; P) with methacroylcholine chloride (MCC; C) and anionic random copolymers (PSn) consisting of MPC and potassium 3-(methacryloyloxy)propanesulfonate (MPS; S) were prepared via a reversible addition-fragmentation chain transfer method. "m" and "n" represent the compositions (mol %) of the MCC and MPS units in the copolymers, respectively. The degrees of polymerization for the copolymers were 93-99. Water-soluble MPC unit contains a pendant zwitterionic phosphorylcholine group whose charges are neutralized in pendant groups. MCC and MPS units contain the cationic quaternary ammonium and anionic sulfonate groups, respectively. The stoichiometrically charge-neutralized mixture of a matched pair of PCm and PSn aqueous solutions resulted in the spontaneous formation of water-soluble PCm/PSn polyion complex (PIC) micelles. These PIC micelles have the MPC-rich surface and MCC/MPS core. These PIC micelles were characterized using 1H NMR, dynamic and static light scattering, and transmission electron microscopic measurements. The hydrodynamic radius of these PIC micelles depends on the mixing ratio of the oppositely charged random copolymers. The charge-neutralized mixture formed maximum-size PIC micelles.
ABSTRACT
Polymeric drug delivery technology, which allows for medicinal ingredients to enter a cell more easily, has advanced considerably in recent decades. Innovative medication delivery strategies use biodegradable and bio-reducible polymers, and progress in the field has been accelerated by future possible research applications. Natural polymers utilized in polymeric drug delivery systems include arginine, chitosan, dextrin, polysaccharides, poly(glycolic acid), poly(lactic acid), and hyaluronic acid. Additionally, poly(2-hydroxyethyl methacrylate), poly(N-isopropyl acrylamide), poly(ethylenimine), dendritic polymers, biodegradable polymers, and bioabsorbable polymers as well as biomimetic and bio-related polymeric systems and drug-free macromolecular therapies have been employed in polymeric drug delivery. Different synthetic and natural biomaterials are in the clinical phase to mitigate different diseases. Drug delivery methods using natural and synthetic polymers are becoming increasingly common in the pharmaceutical industry, with biocompatible and bio-related copolymers and dendrimers having helped cure cancer as drug delivery systems. This review discusses all the above components and how, by combining synthetic and biological approaches, micro- and nano-drug delivery systems can result in revolutionary polymeric drug and gene delivery devices.
ABSTRACT
Recently, mobile phones have become a potent vector for the transmission of pathogens. In hospitals, the use of the mobile phones by healthcare workers in an unhygienic manner accelerates the spread of nosocomial infection. We aimed to investigate the prevalence of microbiological contamination of mobile phones belonging to clinicians in Bangladesh hospitals. From 100 samples, we identified 69 isolates of bacteria including 22 Staphylococcus aureus; 11 Pseudomonas aeruginosa; 14 Escherichia coli; 6 Salmonella typhi 6 and 16 Staphylococcus epidermidis. On the basis of antibiotic susceptibility test using 11 antibiotics, it has been observed that most of the isolated bacteria became resistant to antibiotics and compared to other isolates, isolates of S. epidermidis and S. typhi were more resistant and sensitive, respectively. About 68.8% isolates showed that their resistance capacities against ampicillin but in contrast, 56.6% isolated were susceptible to imipenem. Azithromycin and imipenem against S. aureus, gentamicin against P. aeruginosa, tetracycline and imipenem against E. coli, tetracycline against S. typhi, and S. epidermidis revealed significant antimicrobial affectivity. We found that mobile phones are potential vectors to spread antibiotic-resistant nosocomial pathogens. Based on the study, an effective disinfection practice for cellular phones used in hospitals should be introduced to prevent the potential of cross-contamination.
ABSTRACT
This study is designed to extract crystalline cellulose from cotton and reinforcing gelatin film for biomedical applications, especially as a wound dressing material for its exceptional biocompatibility and bio-activity. Moreover, gelatin helps in wound healing and crystalline cellulose as additive can improve its properties. Crystalline cellulose was prepared through hydrolysis and the effects of crystalline cellulose loading on the morphology, mechanical properties, and water sensitivity of the nanocomposite were investigated by means of scanning electron microscopy, tensile strength testing, and water absorption testing. Developed biocomposite film showed homogeneous dispersion of crystalline cellulose within the gelatin matrix and strong interfacial adherence between the matrix and reinforcement. Samples were tested for biocompatibility and in vitro cytotoxicity and found to have excellent biocompatibility without having any cytotoxicity. In vivo wound healing study in an animal model showed 40% increased healing than the model dressed by conventional dressing.
