Highly Radical-Polymerizable Methacrylamide Having Dipeptide Structure. Synthesis and Radical Polymerization of N-Methacryloyl-l-leucyl-l-alanine Methyl Ester

Synthesis and characterization of novel poly cysteine methacrylate nanoparticles and their morphology and size studies

Polymer nanoparticles (PNPs) have significantly advanced the field of biomedicine, showcasing the remarkable potential for precise drug delivery, administration of nutraceuticals, diagnostics/imaging applications, and the fabrication of biocompatible materials, among other uses. Despite these promising developments, the invention faces notable challenges related to biodegradability, bioactivity, target-site specificity, particle size, carrier efficiency, and controlled release. Addressing these concerns is essential for optimizing the functionality and impact of PNPs in biomedical applications. Here, new poly cysteine methacrylate nanoparticles (PCMANPs), ca. (200 nm) in size have been synthesized from the cysteine methacrylate (CysMA) monomer using different strategies, including emulsion and inverse emulsion polymerization techniques. The monomer was synthesized using the Michael addition reaction, involving the addition of 3-(acryloyloxy)-2-hydroxypropyl methacrylate to the sulfhydryl group (-SH) of the cysteine (Cys) active site, with the aid of dimethyl phenyl phosphine (DMPP) as a nucleophilic agent as previously reported. To enhance nano-polymerization, a thorough exploration of various initiators, including ammonium persulfate (APS) and 4,4'-azobis (4-cyanovaleric acid) (ACVA), alongside surfactants, such as polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), and sodium dodecyl sulfate (SDS), was conducted. Additionally, critical parameters, such as reaction time, temperature, and solvents, were systematically investigated due to their substantial influence on the shape, size, stability, and morphology of the synthesized polymer nanoparticles. This comprehensive approach aims to optimize the synthesis process, ensuring precise control over the key characteristics of the resulting nanoparticles for enhanced performance in diverse applications. Various characterization techniques, including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), zeta potential, and zeta sizer dynamic light scattering (DLS) analysis, were utilized to investigate purity, morphology, and particle size of the PNPs. As a result, a spherical, monodispersed (homogenized), and stable PCMANP with defined size and morphology was achieved. This may exhibit a remarkable achievement in the future of drug delivery systems and therapeutic index.

Peptide-Based Polymer-Polyoxometalate Supramolecular Structure with a Differed Antimicrobial Mechanism

Because of the increasing prevalence of multidrug resistance feature, several investigations have been so far reported regarding the antibiotic alternative supramolecular bioactive agents made of hybrid assemblies. In this regard, it is well-established that combinational therapy inherited by assembled supramolecular structures can improve the bioactivity to some extent, but their mode of action has not been studied in detail. We provide first direct evidence that the improved mechanism of action of antimicrobial supra-amphiphilic nanocomposites differs largely from their parent antimicrobial peptide-based polymers. For the construction of a hybrid combinational system, we have synthesized side-chain peptide-based antimicrobial polymers via RAFT polymerization and exploited their cationic nature to decorate supra-amphiphilic nanocomposites via interaction with anionic polyoxometalates. Because of cooperative antimicrobial properties of both the polymer and polyoxometalate, the nanocomposites show an enhanced antimicrobial activity with a different antimicrobial mechanism. The cationic stimuli-responsive peptide-based polymers attack bacteria via membrane disruption mechanism, whereas free radical-mediated cell damage is the likely mechanism of polymer-polyoxometalate-based supra-amphiphilic nanocomposites. Thus, our study highlights the different antimicrobial mechanism of combinational systems in detail, which improves our understanding of enhanced antimicrobial efficacy.

Synthesis and characterization of poly(amino acid methacrylate)-stabilized diblock copolymer nano-objects

Two amino acid methacrylates prepared via Michael addition are used as building blocks to prepare novel diblock copolymer nano-objects via polymerisation-induced self-assembly.

A comparison of triazole-forming bioconjugation techniques for constructing comb-shaped peptide-polymer bioconjugates

The grafting-to of a peptide to a side chain functional polymer was investigated using "click" chemistry. Two click reactions were compared: the copper-free strain-promoted azide-alkyne 1,3-cycloaddition (SPAAC) and the traditional copper-catalyzed azide-alkyne 1,3-cycloaddition (CuAAC). For the resulting comb-shaped products, it was found that the steric bulk of the conjugation moiety used in SPAAC limits the degree of grafting for these highly dense systems, whereas CuAAC gives (near) quantitative functionalization.

Polymer-peptide block copolymers - an overview and assessment of synthesis methods

Incorporating peptide blocks into block copolymers opens up new realms of bioactive or smart materials. Because there are such a variety of peptides, polymers, and hybrid architectures that can be imagined, there are many different routes available for the synthesis of these chimera molecules. This review summarizes the contemporary strategies in combining synthesis techniques to create well-defined peptide-polymer hybrids that retain the vital aspects of each disparate block. Living polymerization can be united with the molecular-level control afforded by peptide blocks to yield block copolymers that not only have precisely defined primary structures, but that also interact with other (bio)molecules in a well defined manner.

Synthesis, Characterization and Properties of a Series of Copoly(amide-imide-ether-urethane)s with a New Hard Segment Constituent: Study of the Effect of Hard Segment Content

Two series of thermally modified thermoplastic polyurethane elastomers (TPU)s based on poly(oxytetramethylene glycol) (PTMG) (PT samples), and poly(oxyethylene glycol) (POE) (PO samples) were synthesized from 4,4'-methylene-bis-(4-phenylisocyanate) (MDI) and an aromatic diacid, bis( p-amido benzoic acid)- N-trimellitylimido- L-leucine (BPABTL) (1). The aromatic diacid contains a L-leucine group and a preformed imide ring. The novel diacid was reacted with excess MDI to give an isocyanate terminated oligomer that was subsequently reacted with a polyol to give the poly(amide-imide-ether-urethane)s (PAIEU)s. The properties of the resulting PAIEUs were compared with poly(ether urethane)s without incorporation of BPABTL. The PAIEUs had a constant soft segment (SS) length derived from the polyol (average Mn 1000) but a variable hard block length. Studies were conducted on the effect of hard segment (HS) molar ratio on dynamic mechanical thermal properties, thermal properties, phase separation, crystallinity and solvent resistance of these new PAIEUs.