Synthesis of poly(N-vinylformamide) (PNVF) and its subsequent hydrolysis to convert it to poly(vinyl amine) (PVAm) were performed. Kinetics of acidic and basic hydrolysis of poly(N-vinylformamide) (PNVF), and products of hydrolysis were investigated by using Fourier transform infrared, size exclusion chromatography, 1 H NMR, and 13 C NMR spectroscopies, and thermogravimetric analysis. It was observed that amide groups did not completely transform into amine groups by acidic hydrolysis of PNVF while the conversion of amides into amine groups via basic hydrolysis of PNVF was complete in 12 h, as confirmed by spectroscopic measurements. Results of extensive characterization revealed significant structural and conformational differences between acidic and basic hydrolysis products. Fluorescence spectroscopy was used for the first time to follow the conversion of amide groups into amine groups. The fluorescence intensity of PVAm obtained from basic hydrolysis of PVNF showed significant increase with amide/amine conversion. Finally, PVAm obtained from acidic hydrolysis of PNVF demonstrated potent antimicrobial activity, 10-20 times more, against common pathogens for example, C. albicans as fungal strain and E. coli, S. aureus, B. subtilis, and P. aeruginosa as bacterial strains as compared to PVAm obtained from basic hydrolysis.

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Cationic polymers with primary amine groups that can easily be functionalized or coupled with substrates by complexation or hydrogen bonding are especially advantageous in preparing particles for biomedical applications. Poly(vinyl amine) (PVAm) is a cationic polyelectrolyte containing the highest number of primary amine groups among any other polymers. Here, we introduce a general method in synthesizing PVAm microparticles via a surfactant-free water-in-oil emulsion technique using cyclohexane as the oil phase and aqueous PVAm solution as the dispersed phase. PVAm particles were prepared to employ two different bifunctional chemical crosslinkers, divinyl sulfone (DVS) and poly(ethylene glycol) diglycidyl ether (PEGGE). The prepared particles were further treated with HCl to protonate the amine groups of PVAm within particles. The effect of crosslinker types and pH on the hydrolytic degradation of PVAm particles were also investigated at three different solution pHs, 5.4, 7.4, and 9, to simulate the skin, blood, and intestinal pH environments, respectively. The blood compatibility of the PVAm particles was evaluated by in vitro hemolysis and blood clotting assays. Furthermore, antifungal and antibacterial efficacy of PVAm-based particles and their protonated forms were tested against C. albicans yeast and E. coli, S. aureus, B. subtilis, and P. aeruginosa bacterial strains.

Maltose, a natural disaccharide, was crosslinked with divinyl sulfone to prepare poly(maltose) (p(MAL)) micro/nanoparticles via one step microemulsion system with ≥90% ± 5% yield in a size rage of 0.5-100 μm for the first time. P(MAL) was modified (m-p(MAL)) with ethylenediamine (EDA), polyethyleneimine (PEI), and taurine (TA) to render additional functionalities, that is, amine and sulfate groups. The isoelectronic point of bare p(MAL) particles were calculated at pH 2.2 ± 0.5 and was changed to 1.3 ± 0.5, 4.3 ± 1.0, and 8.1 ± 0.7 for TA (p(MAL)/TA), EDA (p(MAL)/EDA), and PEI (p(MAL)/PEI) modification, respectively. Bare p(MAL) particles were found to be biocompatible up to 2 mg/ml with hemolysis and blood clotting tests, whereas the modified p(MAL) particles were found to be biocompatible at 1 mg/ml concentration. Additionally, it was found that TA-and PEI-modified p(MAL) particles induced blood clotting mechanisms. Sodium diclofenac as model drug was released at proportions of 8.7% ± 1.3%, 3.9% ± 0.2%, 8.8% ± 0.9%, and 31.6% ± 0.4% of the loaded drug in phosphate buffered saline solution from p(MAL), p(MAL)/TA, p(MAL)/EDA, and p(MAL)/PEI, respectively. The inhibition of antimicrobial activity of p(MAL)/PEI particles at 20 mg/ml concentration for Escherichia coli and Staphylococcus aureus strain was determined as 99.86% ± 0.3% and 99.79% ± 0.25%, respectively.

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Due to the intriguing properties of Chitosan (CS), many efforts have been paid for CS‐based fiber preparation. As it is impossible to prepare CS fiber directly, facilitating polymers such as polyvinyl alcohol (PVA) possessing necessary properties that enable CS‐based fiber fabrication is used. For this purpose, 3 wt% of CS in 90% acetic acid solution and 6 wt% PVA solution in DI water used in CS/PVA fiber preparation at different proportions for example, 2:1, 9:1 and 10:1 by weight to fabricate fibers by electrospinning method. Furthermore, to render fluorescent property to CS/PVA (9:1) fibers, N‐doped carbon dots (C‐dots) added into fiber precursor during fiber preparation. The emission peak of C‐dots based fibers that with fluorescent features was observed at around 436 nm. The morphological, structural and, thermal characterizations of CS‐based fibers were done with scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analyzer, respectively. Anti‐bacterial activity of bare CS/PVA was increased with the increase in amounts of C‐dots embedding. The inhibition of zone of CS/PVA (9:1) fibers was increased from 1.8 ± 0.2 cm to 2.1 ± 0.3 cm and 2.9 ± 0.4 cm against E. coli by increasing the amounts of C‐dots from 2.9 mg and 5 mg. Also, the same behavior was observed against S. aureus where the inhibition zone is increased from 2.5 ± 0.1 cm to 3.2 and 3.5 cm by doubling the C‐dots amounts in CS/PVA fiber. Moreover, bare and C‐dots containing CS/PVA fibers were found blood compatible (nonhemolytic) up to 1 mg/mL concentration according to hemolysis and blood clotting tests.

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