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Molecules (Basel, Switzerland) Sep 2022In order to reduce environmental pollution and resource waste, food packaging materials should not only have good biodegradable ability but also effective antibacterial... (Review)
Review
In order to reduce environmental pollution and resource waste, food packaging materials should not only have good biodegradable ability but also effective antibacterial properties. Poly(lactic acid) (PLA) is the most commonly used biopolymer for food packaging applications. PLA has good physical properties, mechanical properties, biodegradability, and cell compatibility but does not have inherent antibacterial properties. Therefore, antibacterial packaging materials based on PLA need to add antibacterial agents to the polymer matrix. Natural antibacterial agents are widely used in food packaging materials due to their low toxicity. The high volatility of natural antibacterial agents restricts their application in food packaging materials. Therefore, appropriate processing methods are particularly important. This review introduces PLA-based natural antibacterial food packaging, and the composition and application of natural antibacterial agents are discussed. The properties of natural antibacterial agents, the technology of binding with the matrix, and the effect of inhibiting various bacteria are summarized.
Topics: Anti-Bacterial Agents; Biopolymers; Food Packaging; Polyesters; Polymers
PubMed: 36144687
DOI: 10.3390/molecules27185953 -
Small (Weinheim An Der Bergstrasse,... Apr 2016Speed, resolution and sensitivity of today's fluorescence bioimaging can be drastically improved by fluorescent nanoparticles (NPs) that are many-fold brighter than... (Review)
Review
Speed, resolution and sensitivity of today's fluorescence bioimaging can be drastically improved by fluorescent nanoparticles (NPs) that are many-fold brighter than organic dyes and fluorescent proteins. While the field is currently dominated by inorganic NPs, notably quantum dots (QDs), fluorescent polymer NPs encapsulating large quantities of dyes (dye-loaded NPs) have emerged recently as an attractive alternative. These new nanomaterials, inspired from the fields of polymeric drug delivery vehicles and advanced fluorophores, can combine superior brightness with biodegradability and low toxicity. Here, we describe the strategies for synthesis of dye-loaded polymer NPs by emulsion polymerization and assembly of pre-formed polymers. Superior brightness requires strong dye loading without aggregation-caused quenching (ACQ). Only recently several strategies of dye design were proposed to overcome ACQ in polymer NPs: aggregation induced emission (AIE), dye modification with bulky side groups and use of bulky hydrophobic counterions. The resulting NPs now surpass the brightness of QDs by ≈10-fold for a comparable size, and have started reaching the level of the brightest conjugated polymer NPs. Other properties, notably photostability, color, blinking, as well as particle size and surface chemistry are also systematically analyzed. Finally, major and emerging applications of dye-loaded NPs for in vitro and in vivo imaging are reviewed.
Topics: Fluorescent Dyes; Molecular Imaging; Nanoparticles; Polymers
PubMed: 26901678
DOI: 10.1002/smll.201503396 -
Current Protocols in Chemical Biology Dec 2020Reversible addition-fragmentation chain-transfer (RAFT) polymerization is a commonly used polymerization methodology to generate synthetic polymers. The products of RAFT...
Reversible addition-fragmentation chain-transfer (RAFT) polymerization is a commonly used polymerization methodology to generate synthetic polymers. The products of RAFT polymerization, i.e., RAFT polymers, have been widely employed in several biologically relevant areas, including drug delivery, biomedical imaging, and tissue engineering. In this article, we summarize a synthetic methodology to display an azide group at the chain end of a RAFT polymer, thus presenting a reactive site on the polymer terminus. This platform enables a click reaction between azide-terminated polymers and alkyne-containing molecules, providing a broadly applicable scaffold for chemical and bioconjugation reactions on RAFT polymers. We also highlight applications of these azide-terminated RAFT polymers in fluorophore labeling and for promoting organelle targeting capability. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Synthesis of the azide derivatives of chain transfer agent and radical initiator Basic Protocol 2: Installation of an azide group on the α-end of RAFT polymers Alternate Protocol: Installation of an azide group on the ω-end of RAFT polymers Basic Protocol 3: Click reaction between azide-terminated RAFT polymers and alkyne derivatives.
Topics: Azides; Click Chemistry; Diagnostic Imaging; Drug Delivery Systems; Polymerization; Polymers; Tissue Engineering
PubMed: 33207082
DOI: 10.1002/cpch.85 -
Science Progress 2023The ceramic-polymer composite materials are widely known for their exceptional mechanical and biological properties. Polycaprolactone (PCL) is a biodegradable polymer... (Review)
Review
The ceramic-polymer composite materials are widely known for their exceptional mechanical and biological properties. Polycaprolactone (PCL) is a biodegradable polymer material extensively used in various biomedical applications. At the same time, barium titanate (BT), a ceramic material, exhibits piezoelectric properties similar to bone, which is essential for osseointegration. Furthermore, a composite material that combines the benefits of PCL and BT results in an innovative composite material with enhanced properties for biomedical applications. Thus, this review is organised into three sections. Firstly, it aims to provide an overview of the current research on evaluating biological properties, including antibacterial activity, cytotoxicity and osseointegration, of PCL polymeric matrices in its pure form and reinforced structures with ceramics, polymers and natural extracts. The second section investigates the biological properties of BT, both in its pure form and in combination with other supporting materials. Finally, the third section provides a summary of the biological properties of the PCLBT composite material. Furthermore, the existing challenges of PCL, BT and their composites, along with future research directions, have been presented. Therefore, this review will provide a state-of-the-art understanding of the biological properties of PCL and BT composites as potential futuristic materials in biomedical applications.
Topics: Biocompatible Materials; Barium; Polyesters; Polymers
PubMed: 38031343
DOI: 10.1177/00368504231215942 -
Advanced Science (Weinheim,... May 2022Polymer indicators are autonomous responsive materials that provide an optical signal of a specific exposure in time. This review describes the different polymer systems... (Review)
Review
Polymer indicators are autonomous responsive materials that provide an optical signal of a specific exposure in time. This review describes the different polymer systems utilized to obtain indicators based on structural color. Structural color originates from the interaction of light with a periodic nanostructured polymer which causes a specific wavelength to be reflected. This reflected light can be used for fabricating battery-free indicators that show visible structural color changes upon exposure to a stimulus or analyte. In this review, the typical structural color response types categorized by stimulus are discussed and compared. Furthermore, the steps toward possible applications of optical indicators based on structural colored polymers are outlined.
Topics: Color; Nanostructures; Polymers
PubMed: 35277942
DOI: 10.1002/advs.202200399 -
Molecules (Basel, Switzerland) Jul 2020Renewable nanocellulose materials received increased attention owing to their small dimensions, high specific surface area, high mechanical characteristics,...
Renewable nanocellulose materials received increased attention owing to their small dimensions, high specific surface area, high mechanical characteristics, biocompatibility, and compostability. Nanocellulose coatings are among many interesting applications of these materials to functionalize different by composition and structure surfaces, including plastics, polymer coatings, and textiles with broader applications from food packaging to smart textiles. Variations in porosity and thickness of nanocellulose coatings are used to adjust a load of functional molecules and particles into the coatings, their permeability, and filtration properties. Mechanical stability of nanocellulose coatings in a wet and dry state are critical characteristics for many applications. In this work, nanofibrillated and nanocrystalline cellulose coatings deposited on the surface of polymer films and textiles made of cellulose, polyester, and nylon are studied using atomic force microscopy, ellipsometry, and T-peel adhesion tests. Methods to improve coatings' adhesion and stability using physical and chemical cross-linking with added polymers and polycarboxylic acids are analyzed in this study. The paper reports on the effect of the substrate structure and ability of nanocellulose particles to intercalate into the substrate on the coating adhesion.
Topics: Cellulose; Food Packaging; Mechanical Tests; Nanofibers; Nanoparticles; Nanostructures; Nylons; Permeability; Physical Phenomena; Polymers; Textiles
PubMed: 32708592
DOI: 10.3390/molecules25143238 -
Analytical Chemistry Sep 2023Polymer nanoparticles are widely used in drug delivery and are also a potential concern due to the increased burden of nano- or microplastics in the environment. In...
Polymer nanoparticles are widely used in drug delivery and are also a potential concern due to the increased burden of nano- or microplastics in the environment. In order to use polymer nanoparticles safely and understand their mechanism of action, it is useful to know where within cells and tissues they end up. To this end, we labeled polymer nanoparticles with nanodiamond particles. More specifically, we have embedded nanodiamond particles in the polymer particles and characterized the composites. Compared to conventional fluorescent dyes, these labels have the advantage that nanodiamonds do not bleach or blink, thus allowing long-term imaging and tracking of polymer particles. We have demonstrated this principle both in cells and entire liver tissues.
Topics: Nanodiamonds; Plastics; Fluorescent Dyes; Drug Delivery Systems; Polymers
PubMed: 37612789
DOI: 10.1021/acs.analchem.3c01452 -
Dental Materials : Official Publication... Apr 2021This research explores the use of polymer brushes for surface treatment of fillers used in polymer-based dental restoratives with focus on shrinkage stress reduction....
OBJECTIVES
This research explores the use of polymer brushes for surface treatment of fillers used in polymer-based dental restoratives with focus on shrinkage stress reduction. The influence of interfacial reactive groups on shrinkage stress is explored.
METHODS
Oligomers of varying lengths and with varying number of reactive groups along the length were synthesized by modifying commercial oligomers. Surface of silica fillers (OX50) was treated with methylaminopropyltrimethoxysilane and this was further reacted with the synthesized oligomers to obtain a series of polymer brushes on the surface. Fillers modified with γ-methacryloxypropyltrimethoxysilane were used as a control. Filler surface treatment was confirmed using diffuse reflectance spectroscopy and thermogravimetric analysis. Fillers were added at 30 wt % to a resin made of BisGMA/TEGDMA and polymerization kinetics, shrinkage stress, volumetric shrinkage, flexural strength and modulus, viscosity were measured.
RESULTS
Composites with polymer brush functionalized fillers showed up to a 30 % reduction in shrinkage stress as compared to the control, with no reduction in flexural strength and modulus. Shrinkage stress reduced with increasing length of the polymer brush and increased with increase in number of reactive groups along the length of the polymer brush.
SIGNIFICANCE
The interface between inorganic fillers and an organic polymer matrix has been utilized to reduce shrinkage stress in a composite with no compromise in mechanical properties. This study gives insights into the stress development mechanism at the interface.
Topics: Composite Resins; Materials Testing; Methacrylates; Pliability; Polyethylene Glycols; Polymers; Polymethacrylic Acids; Stress, Mechanical; Surface Properties
PubMed: 33573842
DOI: 10.1016/j.dental.2021.01.013 -
Molecular Pharmaceutics Feb 2022Amorphous solid dispersions (ASDs) are of great interest due to their ability to enhance the delivery of poorly soluble drugs. Recent studies have shown that, in...
Amorphous solid dispersions (ASDs) are of great interest due to their ability to enhance the delivery of poorly soluble drugs. Recent studies have shown that, in addition to acting as a crystallization inhibitor, the polymer in an ASD plays a role in controlling the rate of drug release, notably in congruently releasing formulations, where both the drug and polymer have similar normalized release rates. The aim of this study was to compare the solid-state stability and release performance of ASDs when formulated with neutral and enteric polymers. One neutral (polyvinylpyrrolidone-vinyl acetate copolymer, PVPVA) and four enteric polymers (hypromellose acetate succinate; hypromellose phthalate; cellulose acetate phthalate, CAP; methacrylic acid-methyl methacrylate copolymer, Eudragit L 100) were used to formulate binary ASDs with lumefantrine, a hydrophobic and weakly basic antimalarial drug. The normalized drug and polymer release rates of lumefantrine-PVPVA ASDs up to 35% drug loading (DL) were similar and rapid. No drug release from PVPVA systems was detected when the DL was increased to 40%. In contrast, ASDs formulated with enteric polymers showed a DL-dependent decrease in the release rates of both the drug and polymer, whereby release was slower than for PVPVA ASDs for DLs < 40% DL. Drug release from CAP and Eudragit L 100 systems was the slowest and drug amorphous solubility was not achieved even at 5% DL. Although lumefantrine-PVPVA ASDs showed fast release, they also showed rapid drug crystallization under accelerated stability conditions, while the ASDs with enteric polymers showed much greater resistance to crystallization. This study highlights the importance of polymer selection in the formulation of ASDs, where a balance between physical stability and dissolution release must be achieved.
Topics: Drug Liberation; Drug Stability; Lumefantrine; Pharmaceutical Preparations; Polymers; Solubility
PubMed: 34494842
DOI: 10.1021/acs.molpharmaceut.1c00481 -
Molecules (Basel, Switzerland) Jul 2020Molecularly imprinted polymers (MIPs) are specific crosslinked polymers that exhibit binding sites for template molecules. MIPs have been developed in various... (Review)
Review
Molecularly imprinted polymers (MIPs) are specific crosslinked polymers that exhibit binding sites for template molecules. MIPs have been developed in various application areas of biology and chemistry; however, MIPs have some problems, including an irregular material shape. In recent years, studies have been conducted to overcome this drawback, with the synthesis of uniform microsphere MIPs or molecularly imprinted microspheres (MIMs). The polymer microsphere is limited to a minimum size of 5 nm and a molecular weight of 10,000 Da. This review describes the methods used to produce MIMs, such as precipitation polymerisation, controlled/'Living' radical precipitation polymerisation (CRPP), Pickering emulsion polymerisation and suspension polymerisation. In addition, some green chemistry aspects and future perspectives will also be given.
Topics: Emulsions; Humans; Microspheres; Molecular Imprinting; Polymerization; Polymers
PubMed: 32708849
DOI: 10.3390/molecules25143256