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Polymers Apr 2024The development of a hydrogel material with a modified chemical structure of poly(vinyl alcohol) (PVA) and silk fibroin (SF) using glycidyl methacrylate (GMA) (denoted...
Development of Biphasic Injectable Hydrogels for Meniscus Scaffold from Photocrosslinked Glycidyl Methacrylate-Modified Poly(Vinyl Alcohol)/Glycidyl Methacrylate-Modified Silk Fibroin.
The development of a hydrogel material with a modified chemical structure of poly(vinyl alcohol) (PVA) and silk fibroin (SF) using glycidyl methacrylate (GMA) (denoted as PVA-g-GMA and SF-g-GMA) is an innovative approach in the field of biomaterials and meniscus tissue engineering in this study. The PVA-g-GMA/SF-g-GMA hydrogel was fabricated using different ratios of PVA-g-GMA to SF-g-GMA: 100/0, 75/25, 50/50, 25/75, and 0/100 (/ of dry substances), using lithium phenyl (2,4,6-trimethylbenzoyl)phosphinate (LAP) as a free radical photoinitiator, for 10 min at a low ultraviolet (UV) intensity (365 nm, 6 mW/cm). The mechanical properties, morphology, pore size, and biodegradability of the PVA-g-GMA/SF-g-GMA hydrogel were investigated. Finally, for clinical application, human chondrocyte cell lines (HCPCs) were mixed into PVA-g-GMA/SF-g-GMA solutions and fabricated into hydrogel to study the viability of live and dead cells and gene expression. The results indicate that as the SF-g-GMA content increased, the compressive modulus of the PVA-g-GMA/SF-g-GMA hydrogel dropped from approximately 173 to 11 kPa. The degradation rates of PVA-g-GMA/SF-g-GMA 100/0, 75/25, and 50/50 reached up to 15.61%, 17.23%, and 18.93% in 4 months, respectively. In all PVA-g-GMA/SF-g-GMA conditions on day 7, chondrocyte cell vitality exceeded 80%. The PVA-g-GMA/SF-g-GMA 75:25 and 50:50 hydrogels hold promise as a biomimetic biphasic injectable hydrogel for encapsulated augmentation, offering advantages in terms of rapid photocurability, tunable mechanical properties, favorable biological responses, and controlled degradation.
PubMed: 38675012
DOI: 10.3390/polym16081093 -
Toxics Apr 2024The most common pesticide agents are organophosphates and phosphides, aluminum phosphide (ALP) in particular. ALP is a major cause of suicidal poisoning in many...
The most common pesticide agents are organophosphates and phosphides, aluminum phosphide (ALP) in particular. ALP is a major cause of suicidal poisoning in many countries. In other countries, the problem of accidental, mainly occupational-related, poisoning is also real and actual. Almost two thirds of individuals in poisoning cases have died. This case report describes a case of a patient with accidental ALP intoxication. The origin of the poisoning was the fumigation of stored grain in an agricultural building adjacent to the building in which patient was temporarily housed, while both buildings were connected by an underground corridor, through which the released poison gas penetrated. The case was originally presented by the rescuers as well as healthcare professionals of the local hospital as carbon monoxide intoxication, which has a similar symptomatology as ALP intoxication. The patient was treated comprehensively, including using the HBOT method, which is very unique in the case of phosphine intoxication in human medicine, with an excellent final clinical outcome. This was the first described case of HBOT for ALP intoxication in clinical medicine, although the HBOT indication itself became a coincidence in this case. Further studies must be undertaken to demonstrate the effectiveness of HBOT in treating patients with ALP poisoning.
PubMed: 38668495
DOI: 10.3390/toxics12040272 -
Chemical Science Apr 2024P(v) iminophosphorane compounds are accessed electrochemical oxidation of commercially available P(iii) phosphines, including mono-, di- and tri-dentate phosphines, as...
P(v) iminophosphorane compounds are accessed electrochemical oxidation of commercially available P(iii) phosphines, including mono-, di- and tri-dentate phosphines, as well as chiral phosphines. The reaction uses inexpensive bis(trimethylsilyl)carbodiimide as an efficient and safe aminating reagent. DFT calculations, cyclic voltammetry, and NMR studies provide insight into the reaction mechanism. The proposed mechanism reveals a special case of sequential paired electrolysis. DFT calculations of the frontier orbitals of an iminophosphorane are compared with those of the analogous phosphines and phosphine oxides. X-ray crystallographic studies of the ligands as well as a Ni-coordination complex provide structural insight for these ligands. The utility of these iminophosphoranes as ligands is demonstrated in nickel-catalyzed cross-electrophile couplings including C(sp)-C(sp) and C(sp)-C(sp) couplings, an electrochemically driven C-N cross-coupling, and a photochemical arylative C(sp)-H functionalization. In some cases, these new ligands provide improved performance over commonly used sp--based ligands ( 4,4'-di--butyl-2,2'-bipyridine).
PubMed: 38665537
DOI: 10.1039/d3sc05357a -
Chemical Science Apr 2024Recognition-encoded melamine oligomers (REMO) are synthetic polymers with an alternating 1,3,5-triazine-piperazine backbone and side chains equipped with either a phenol...
Recognition-encoded melamine oligomers (REMO) are synthetic polymers with an alternating 1,3,5-triazine-piperazine backbone and side chains equipped with either a phenol or phosphine oxide recognition unit. Here, we describe an automated method for highly efficient solid-phase synthesis (SPS) of REMO of any specified length and sequence. These SPS protocols are amongst the most robust reported to date, as demonstrated by the synthesis of a mixed-sequence 42-mer, which was obtained in excellent crude purity on a 100 mg scale. Starting from loaded Wang resin and dichlorotriazine monomer building blocks, the SPS methods were automated and optimised on a commercial peptide synthesiser. Major side products were identified using LCMS, and the undesired side reactions were suppressed by the choice of resin, solvent and coupling conditions. REMO have been shown to form high-fidelity length- and sequence-selective H-bonded duplexes, analogous to nucleic acids, and automated synthesis will facilitate exploration of related functional properties, such as molecular replication and programmable self-assembly.
PubMed: 38665524
DOI: 10.1039/d4sc00973h -
RSC Advances Apr 2024Polymer nanoparticles (PNPs) have significantly advanced the field of biomedicine, showcasing the remarkable potential for precise drug delivery, administration of...
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), (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.
PubMed: 38665499
DOI: 10.1039/d4ra00067f -
Chemical Science Apr 2024We describe the first experimental example of a theoretically predicted Frustrated Lewis Trio (FLT). A tetradentate PNNP ligand is used to stabilise a highly...
We describe the first experimental example of a theoretically predicted Frustrated Lewis Trio (FLT). A tetradentate PNNP ligand is used to stabilise a highly electrophilic [TiCl] fragment in a way that results in two equally long and frustrated Ti-P bonds. A combined experimental and computational approach revealed a distinct role of each Lewis basic phosphine in the heterolytic activation of chemical bonds. This dual functionality is characterised by a pendulum-like hemilability, where one of the phosphines acts as a nucleophile while the other serves as a hemilabile ligand that dynamically tunes the Ti-P distance as a function of the required electron density at the Ti centre.
PubMed: 38638227
DOI: 10.1039/d3sc06789k -
Inorganic Chemistry Apr 2024Homogeneous transition metal catalysis is a constantly developing field in chemical sciences. A growing interest in this area is photoswitchable catalysis, which pursues...
Homogeneous transition metal catalysis is a constantly developing field in chemical sciences. A growing interest in this area is photoswitchable catalysis, which pursues modulation of catalyst activity through noninvasive light irradiation. Phosphorus ligands are excellent targets to accomplish this goal by introducing photoswitchable moieties; however, only a limited number of examples have been reported so far. In this work, we have developed a series of palladium complexes capable of catalyzing the Stille coupling reaction that contain photoisomerizable phosphine ligands based on dithienylethene switches. Incorporation of electron-withdrawing substituents into these dithienylethene moieties allows variation of the electron density on the phosphorus atom of the ligands upon light irradiation, which in turn leads to a modulation of the catalytic properties of the formed complexes and their activity in a model Stille coupling reaction. These results are supported by theoretical computations, which show that the energy barriers for the rate-determining steps of the catalytic cycle decrease when the photoswitchable phosphine ligands are converted to their closed state.
PubMed: 38624066
DOI: 10.1021/acs.inorgchem.3c04423 -
Molecules (Basel, Switzerland) Apr 2024We previously revealed that phosphine-boranes can function as molecular frameworks for biofunctional molecules. In the present study, we exploited the diversity of...
We previously revealed that phosphine-boranes can function as molecular frameworks for biofunctional molecules. In the present study, we exploited the diversity of available phosphines to design and synthesize a series of -(trifluoromethyl)phenyl phosphine-borane derivatives as novel progesterone receptor (PR) antagonists. We revealed that the synthesized phosphine-borane derivatives exhibited Log values in a predictable manner and that the P-H group in the phosphine-borane was almost nonpolar. Among the synthesized phosphine-boranes, which exhibited PR antagonistic activity, -(4-trifluoromethyl)phenyl tricyclopropylphosphine-borane was the most potent with an IC value of 0.54 μM. A docking simulation indicated that the tricyclopropylphosphine moiety plays an important role in ligand-receptor interactions. These results support the idea that phosphine-boranes are versatile structural options in drug discovery, and the developed compounds are promising lead compounds for further structural development of next-generation PR antagonists.
Topics: Receptors, Progesterone; Boranes; Computer Simulation; Drug Discovery; Phosphines
PubMed: 38611867
DOI: 10.3390/molecules29071587 -
Molecules (Basel, Switzerland) Mar 2024A series of optically pure aziridine phosphines and their corresponding phosphine oxides were synthesized through established chemical methodologies. The compounds were...
A series of optically pure aziridine phosphines and their corresponding phosphine oxides were synthesized through established chemical methodologies. The compounds were systematically investigated for their biological properties. Notably, all synthesized compounds demonstrated moderate antibacterial activity only against the reference strain of . However, compounds and exhibited noteworthy cell viability inhibition of human cervical epithelioid carcinoma HeLa cells and endometrial adenocarcinoma Ishikawa cells. Further studies of these compounds revealed additional biological effects, including disruption of the cell membrane in high concentrations, cell cycle arrest in the S phase, and the induction of reactive oxygen species (ROS). Comparative analysis of the two classes of chiral organophosphorus derivatives of aziridines indicated that chiral phosphine oxides displayed significantly higher biological activity. Consequently, these findings suggest that chiral phosphine oxides may be potential candidates for the development of anticancer drugs. In light of the significant interest in preparations whose structure is based on a three-membered aziridine ring in terms of potential anticancer therapy, this research fits into the current research trend and should constitute a valuable addition to the current state of knowledge and the existing library of aziridine derivatives with anticancer properties.
Topics: Humans; HeLa Cells; Aziridines; Oxides; Phosphines
PubMed: 38611710
DOI: 10.3390/molecules29071430 -
Polymers Mar 2024The present work proposes to investigate the effect of an ultrahigh molecular weight silicone rubber (UHMW-SR) and two ethylene methyl acrylate copolymers (EMA) with...
Phosphorus-Based Flame-Retardant Acrylonitrile Butadiene Styrene Copolymer with Enhanced Mechanical Properties by Combining Ultrahigh Molecular Weight Silicone Rubber and Ethylene Methyl Acrylate Copolymer.
The present work proposes to investigate the effect of an ultrahigh molecular weight silicone rubber (UHMW-SR) and two ethylene methyl acrylate copolymers (EMA) with different methyl acrylate (MA) content on the mechanical and fire performance of a fireproof acrylonitrile butadiene styrene copolymer (ABS) composite, with an optimum amount of ammonium polyphosphate (APP) and aluminum diethyl phosphinate (AlPi). ABS formulations with a global flame retardant weight content of 20 wt.% (ABS P) were melt-compounded, with and without EMA and UHMW-SR, in a Brabender mixer. During this batch process, ABS P formulations with UHMW-SR and/or EMA registered lower torque values than those of ABS P. By means of scanning electron microscopy (SEM), it was possible to observe that all ABS composites exhibited a homogenous structure without phase separation or particle agglomeration. Slightly improved interfacial interaction between the well-dispersed flame-retardant particles in the presence of EMA and/or UHMW-SR was also noticed. Furthermore, synergies in mechanical properties by adding both EMA and UHMW-SR into ABS P were ascertained. An enhancement of molecular mobility that contributed to the softening of ABS P was observed under dynamic mechanical thermal analysis (DMTA). An improvement of its flexibility, ductility and toughness were also registered under three-point-bending trials, and even more remarkable synergies were noticed in Charpy notched impact strength. Particularly, a 212% increase was achieved when 5 wt.% of EMA with 29 wt.% of MA and 2 wt.% of UHMW-SR in ABS P (ABS E29 S P) were added. Thermogravimetric analysis (TGA) showed that the presence of EMA copolymers in ABS P formulations did not interfere with its thermal decomposition, whereas UHMW-SR presence decreased its thermal stability at the beginning of the decomposition. Although the addition of EMA or UHMW-SR, as well as the combination of both in ABS P increased the pHRR in cone calorimetry, UL 94 V-0 classification was maintained for all flame-retarded ABS composites. In addition, through SEM analysis of cone calorimetry sample residue, a more cohesive surface char layer, with Si-O-C network formation confirmed by Fourier transform infrared (FTIR), was shown in ABS P formulations with UHMW-SR.
PubMed: 38611181
DOI: 10.3390/polym16070923