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Methods in Molecular Biology (Clifton,... 2018Polymer capsules fabricated via layer-by-layer (LbL) assembly have emerged as promising carriers for therapeutic delivery. The versatile assembly technique allows an...
Polymer capsules fabricated via layer-by-layer (LbL) assembly have emerged as promising carriers for therapeutic delivery. The versatile assembly technique allows an extensive choice of materials to be incorporated as constituents of the multilayers, which therefore endow capsules with specific properties and functionalities. This chapter describes protocols for fabrication of LbL-engineered poly(methacrylic acid) (PMA) capsules for applications in gene delivery, including (1) synthesis of building blocks, (2) cargo encapsulation, (3) multilayer film formation, (4) surface modification, and (5) cross-linking of multilayer films and dissolution of particle templates. DNA is adsorbed onto positively charged silica particle templates, followed by formation of polymer films via hydrogen-bonded multilayers of thiol-functionalized PMA and poly(N-vinylpyrrolidone) (PVP). The outer polymer membranes can be surface modified with copolymers of PMA and poly(ethylene glycol) (PEG). Upon film stabilization and dissolution of particle templates, disulfide-cross-linked DNA-loaded PMA capsules are obtained, which serve as therapeutic carriers that can degrade and facilitate cargo release in intracellular reducing environment.
Topics: Capsules; Cross-Linking Reagents; DNA; Disulfides; Drug Carriers; Drug Delivery Systems; Gene Transfer Techniques; Hydrophobic and Hydrophilic Interactions; Polyethylene Glycols; Polymers; Polymethacrylic Acids; Sulfhydryl Compounds
PubMed: 29679323
DOI: 10.1007/978-1-4939-7741-3_6 -
Advanced Materials (Deerfield Beach,... Dec 2021Embedding catalysts inside of plastics affords accelerated chemical modification with programmable latency and pathways. Nanoscopically embedded enzymes can lead to...
Embedding catalysts inside of plastics affords accelerated chemical modification with programmable latency and pathways. Nanoscopically embedded enzymes can lead to near-complete degradation of polyesters via chain-end mediated processive depolymerization. The overall degradation rate and pathways have a strong dependence on the morphology of semicrystalline polyesters. Yet, most studies to date focus on pristine polymers instead of mixtures that contain additives and other components despite their nearly universal use in plastic production. Here, additives are introduced to purposely change the morphology of polycaprolactone (PCL) by increasing the bending and twisting of crystalline lamellae. These morphological changes immobilize chain ends preferentially at the crystalline/amorphous interfaces and limit chain-end accessibility by the embedded processive enzyme. This chain-end redistribution reduces the polymer-to-monomer conversion from >95% to less than 50%, causing formation of highly crystalline plastic pieces, including microplastics. By synergizing both random chain scission and processive depolymerization, it is feasible to navigate morphological changes in polymer/additive blends and to achieve near-complete depolymerization. The random scission enzymes in the amorphous domains create new chain ends that are subsequently bound and depolymerized by processive enzymes. Present studies further highlight the importance to consider how the host polymer's morphologies affect the reactions catalyzed by embedded catalytic species.
Topics: Plastics; Polyesters; Polymers
PubMed: 34623716
DOI: 10.1002/adma.202105707 -
Nature Chemistry Feb 2012Synthetic polymers are widely used materials, as attested by a production of more than 200 millions of tons per year, and are typically composed of linear repeat units....
Synthetic polymers are widely used materials, as attested by a production of more than 200 millions of tons per year, and are typically composed of linear repeat units. They may also be branched or irregularly crosslinked. Here, we introduce a two-dimensional polymer with internal periodicity composed of areal repeat units. This is an extension of Staudinger's polymerization concept (to form macromolecules by covalently linking repeat units together), but in two dimensions. A well-known example of such a two-dimensional polymer is graphene, but its thermolytic synthesis precludes molecular design on demand. Here, we have rationally synthesized an ordered, non-equilibrium two-dimensional polymer far beyond molecular dimensions. The procedure includes the crystallization of a specifically designed photoreactive monomer into a layered structure, a photo-polymerization step within the crystal and a solvent-induced delamination step that isolates individual two-dimensional polymers as free-standing, monolayered molecular sheets.
Topics: Anthracenes; Crystallization; Microscopy, Atomic Force; Polymers; Solvents
PubMed: 22437713
DOI: 10.1038/nchem.1265 -
Macromolecular Rapid Communications Jan 2023The rapid development of 4D printing provides a potential strategy for the fabrication of deployable medical devices (DMD). The minimally invasive surgery to implant the...
The rapid development of 4D printing provides a potential strategy for the fabrication of deployable medical devices (DMD). The minimally invasive surgery to implant the DMD into the body is critical, 4D printing DMD allows the well-defined device to be implanted with a high-compacted shape and transformed into their designed shape to meet the requirement. Herein, a 4D printing tissue engineering material is developed with excellent biocompatibility and shape memory effect based on the photocrosslinked polycaprolactone (PCL). The fast thiol-acrylate click reaction is applied for photocrosslinking of the acrylates capped star polymer (s-PCL-MA) with poly-thiols, that enable the 3D printing for the DMD fabrication. The cell viability, erythrocyte hemolysis, and platelet adhesion results indicate the excellent biocompatibility of the 4D printing polymer, especially the biological subcutaneous implantation results confirm the promote tissue growth and good histocompatibility. A 4D printing stent with deformable shape and recovery at a temperature close to human body temperature demonstrated the potential application as DMD. In addition, the everolimus is loaded to the polymer (ps1-PCL) through host-guest coordination with β-cyclodextrin as the core of the star polymer, which shows sustained drug release and improved body's inflammatory response.
Topics: Humans; Smart Materials; Polymers; Tissue Engineering; Drug Liberation; Printing, Three-Dimensional
PubMed: 36029168
DOI: 10.1002/marc.202200553 -
Macromolecular Rapid Communications Sep 2013The synthesis of novel luminescent polymer containing p-phenylene-ethynylene and 9,12-linked o-carborane units alternately in the main chain is reported. The obtained...
The synthesis of novel luminescent polymer containing p-phenylene-ethynylene and 9,12-linked o-carborane units alternately in the main chain is reported. The obtained polymer exhibits intense blue photoluminescence, providing the first insights into the optical properties of a 9,12-disubstituted o-carborane dye. π-Conjugated substituent at 9 and/or 12-positions in o-carborane is electrically independent, and both the HOMO and the LUMO levels slightly increase, whereas LUMO of the π-conjugated substituent at 1 and/or 2-positions in o-carborane decrease. Thus, it is deduced that polymers consisting of the 9,12-linked o-carborane unit are able to be applied as light-emitting materials.
Topics: Boron Compounds; Luminescence; Polymers
PubMed: 23857676
DOI: 10.1002/marc.201300368 -
Angewandte Chemie (International Ed. in... Jan 2014More participants, yet efficient reactions: Multicomponent reactions (MCRs) have found application in polymer chemistry both in the synthesis of multifunctional monomers...
More participants, yet efficient reactions: Multicomponent reactions (MCRs) have found application in polymer chemistry both in the synthesis of multifunctional monomers and in post-polymerization modification. Examples include the Passerini three-component reaction, the Ugi four-component reaction, and the copper-catalyzed MCR.
Topics: Chemistry, Organic; Polymerization; Polymers
PubMed: 24302633
DOI: 10.1002/anie.201305538 -
Angewandte Chemie (International Ed. in... Aug 2013
Topics: Electrodes; Free Radicals; Particle Size; Polymerization; Polymers
PubMed: 23818459
DOI: 10.1002/anie.201304449 -
ACS Infectious Diseases Mar 2020Multidrug-resistant (MDR) bacteria have emerged quickly and have caused serious nosocomial infections. It is urgent to develop novel antimicrobial agents for treating...
Multidrug-resistant (MDR) bacteria have emerged quickly and have caused serious nosocomial infections. It is urgent to develop novel antimicrobial agents for treating MDR bacterial infections. In this study, we isolated 45 strains of bacteria from hospital patients and found shockingly that most of these strains were MDR to antimicrobial drugs. This inspired us to explore antimicrobial peptide polymers as synthetic mimics of host defense peptides in combating drug-resistant bacteria and the formidable antimicrobial challenge. We found that peptide polymer 80:20 DM:Bu (where DM is a hydrophilic/cationic subunit and Bu is a hydrophobic subunit) displayed fast bacterial killing, broad spectrum, and potent activity against clinically isolated strains of MDR bacteria. Moreover, peptide polymer 80:20 DM:Bu displayed potent antibacterial efficacy, comparable to the performance of polymyxin B, in a () infected rat full-thickness wound model. The peptide polymer can be easily synthesized from ring-opening polymerization with remarkable reproducibility in structural properties and biological activities. The peptide polymer's potent and broad spectrum antimicrobial activities against MDR bacteria and , resistance to proteolysis, and high structural diversity altogether imply a great potential of peptide polymer 80:20 DM:Bu in antimicrobial applications as synthetic mimics of host defense peptides.
Topics: Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Bacteria; Drug Resistance, Multiple, Bacterial; Female; Microbial Sensitivity Tests; Polymers; Pseudomonas Infections; Pseudomonas aeruginosa; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Wound Infection
PubMed: 31922723
DOI: 10.1021/acsinfecdis.9b00410 -
Journal of Chromatography. A Feb 2019Currently, a lot of research effort in polymer analysis by liquid chromatographic techniques, including size exclusion chromatography (SEC), polymer HPLC or liquid...
Currently, a lot of research effort in polymer analysis by liquid chromatographic techniques, including size exclusion chromatography (SEC), polymer HPLC or liquid chromatography at critical conditions, is done aiming to improve separation performance. In this study, novel gradient protocols were investigated primarily based on gradient polymer elution chromatography (GPEC). Starting with linear gradients and stepwise gradients a new periodic saw tooth gradient profile was developed and optimized. Optimum settings for the saw tooth gradient design were evaluated by design of experiments (DoE) based on Taguchi's methodology for various types of stationary phases. The gain of peak resolution was dependent on the effective gradient step height. The optimized protocol enabled high-resolution polymer HPLC (HRP-HPLC) separations with common HPLC instruments. The quality of separation was evaluated by heart-cut fraction collection of HRP-HPLC and subsequent determination of the individual fractions by SEC or MALDI-ToF mass spectrometry. Finally, different types of polymers, such as PVC, PDMS, PMMA, or PPG, were studied with the new method and a universal applicability was shown.
Topics: Chemistry Techniques, Analytical; Chromatography, High Pressure Liquid; Mass Spectrometry; Polymers
PubMed: 30580959
DOI: 10.1016/j.chroma.2018.11.075 -
Journal of Pharmaceutical Sciences Jan 2022To reduce the risk of infection during intravitreal injections, the external surface of prefilled syringes (PFSs) must be sterilized. Usually, ethylene oxide (EO) gas or...
To reduce the risk of infection during intravitreal injections, the external surface of prefilled syringes (PFSs) must be sterilized. Usually, ethylene oxide (EO) gas or vaporized hydrogen peroxide (VHP) is used for sterilization. More recently, nitrogen dioxide (NO) gas sterilization has been developed. It is known that gas permeability is approximately zero into glass-PFSs. However, polymer-PFSs (P-PFSs) have relatively high gas permeability. Therefore, there are concerns about the potential impact of external surface sterilization on drug solutions in P-PFSs. In this study, P-PFSs [filled with water for injection (WFI) or human serum albumin (HSA) solution] were externally sterilized using EO, VHP, and NO gases. For the WFI-filled syringes, the concentration of each gas that ingressed into the WFI was measured. For the HSA solution-filled syringes, the physical and chemical degradation of HSA molecules by each sterilant gas was quantified. For the EO- or VHP-sterilized syringes, the ingressed EO or hydrogen peroxide (HO) molecules were detected in the filled WFI. Additionally, EO-adducted or oxidized HSA molecules were observed in the HSA-filled syringes. In contrast, the NO-sterilized WFI-filled syringes exhibited essentially immeasurable ingressed NO, and protein degradation was not detected in HSA-filled syringes.
Topics: Gases; Humans; Hydrogen Peroxide; Polymers; Sterilization; Syringes
PubMed: 34499900
DOI: 10.1016/j.xphs.2021.09.003