Poly(methacrylic acid) derivatives. 5. Microcalorimetric study of poly(N-methacryloyl-L-alanine) and poly(N-methacryloyl-L-alanine-co-N-phenylmethacrylamide) in aqueous solutions

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.

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.

Polymers derived from the amino acid L-tyrosine: polycarbonates, polyarylates and copolymers with poly(ethylene glycol)

The natural amino acid L-tyrosine is a major nutrient having a phenolic hydroxyl group. This feature makes it possible to use derivatives of tyrosine dipeptide as a motif to generate diphenolic monomers, which are important building blocks for the design of biodegradable polymers. Particularly useful monomers are desaminotyrosyl-tyrosine alkyl esters (abbreviated as DTR, where R stands for the specific alkyl ester used). Using this approach, a wide variety of polymers have been synthesized. Here, tyrosine-derived polycarbonates, polyarylates, and polyethers are reviewed with special emphasis on recent developments relating to cellular and in vivo responses, sterilization techniques, surface characterization, drug delivery, and processing and fabrication techniques. The commercial development of tyrosine-derived polycarbonates is most advanced, with one polymer, poly(DTE carbonate) (E=ethyl), being under review by the USA Federal Drug Administration.

Conformations of hydrophobic polyelectrolytes

Recent studies on the (hypercoiled) compact conformation and the pH-induced conformational transition to the extended coil of the hydrophobic poly(acids or bases), which have been well used in industrial and medical circles, are summarized, especially on the basis of our studies on poly(alpha-alkyl acrylic acids) and maleic acid copolymers with hydrophobic aromatic monomers. The stability of the compact conformation and values of various thermodynamic parameters of the transition of the hydrophobic polyelectrolytes suggest the importance of hydrophobic interaction among the side chains to form the compact conformation. Characterization of various physicochemical methods, including 1H-NMR measurements, gives a model of the compact conformation with a more expanded structure than in globular proteins, a free-draining property of the solvent, the conformation fluctuation, etc. Also, the apparent two-state character of each segment in the transition region, a life-time in each state and the cooperative parameter for the compact form formation are discussed. A review of our conformational studies on the hydrophobic-hydrophilic polypeptides is also given. For the anion-induced conformation transition in basic homopoly(alpha-amino acids), hydrophobic characters of the anion and the side chain in the polypeptide are shown to be important, especially in terms of solvation. The difference in the induced conformation by the anion between random and alternating basic copolypeptides is explained by introducing a model which shows the importance of the sequence of hydrophobic and hydrophilic residues in the polypeptide to induce the ordered conformation of the anions. Also, we attempt to explain the difference between the induction of ordered conformation in the basic homo- or copolypeptide in reversed micelles with a large sulfonate (AOT) vs. that in aqueous AOT in terms of the hydrophobic character of the side chains in the polypeptides, AOT and the medium.