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International Journal of Molecular... Oct 2022Finding alternatives to diminish plastic pollution has become one of the main challenges of modern life. A few alternatives have gained potential for a shift toward a... (Review)
Review
Finding alternatives to diminish plastic pollution has become one of the main challenges of modern life. A few alternatives have gained potential for a shift toward a more circular and sustainable relationship with plastics. Biodegradable polymers derived from bio- and fossil-based sources have emerged as one feasible alternative to overcome inconveniences associated with the use and disposal of non-biodegradable polymers. The biodegradation process depends on the environment's factors, microorganisms and associated enzymes, and the polymer properties, resulting in a plethora of parameters that create a complex process whereby biodegradation times and rates can vary immensely. This review aims to provide a background and a comprehensive, systematic, and critical overview of this complex process with a special focus on the mesophilic range. Activity toward depolymerization by extracellular enzymes, biofilm effect on the dynamic of the degradation process, CO evolution evaluating the extent of biodegradation, and metabolic pathways are discussed. Remarks and perspectives for potential future research are provided with a focus on the current knowledge gaps if the goal is to minimize the persistence of plastics across environments. Innovative approaches such as the addition of specific compounds to trigger depolymerization under particular conditions, biostimulation, bioaugmentation, and the addition of natural and/or modified enzymes are state-of-the-art methods that need faster development. Furthermore, methods must be connected to standards and techniques that fully track the biodegradation process. More transdisciplinary research within areas of polymer chemistry/processing and microbiology/biochemistry is needed.
Topics: Carbon Dioxide; Polymers; Biodegradation, Environmental; Plastics; Biodegradable Plastics
PubMed: 36293023
DOI: 10.3390/ijms232012165 -
Molecules (Basel, Switzerland) Oct 2020In recent years, molecularly imprinted polymers (MIPs) have become an excellent solution to the selective and sensitive determination of target molecules in complex... (Review)
Review
In recent years, molecularly imprinted polymers (MIPs) have become an excellent solution to the selective and sensitive determination of target molecules in complex matrices where other similar and relative structural compounds could coexist. Although MIPs show the inherent properties of the polymers, including stability, robustness, and easy/cheap synthesis, some of their characteristics can be enhanced, or new functionalities can be obtained when nanoparticles are incorporated in their polymeric structure. The great variety of nanoparticles available significantly increase the possibility of finding the adequate design of nanostructured MIP for each analytical problem. Moreover, different structures (i.e., monolithic solids or MIPs micro/nanoparticles) can be produced depending on the used synthesis approach. This review aims to summarize and describe the most recent and innovative strategies since 2015, based on the combination of MIPs with nanoparticles. The role of the nanoparticles in the polymerization, as well as in the imprinting and adsorption efficiency, is also discussed through the review.
Topics: Adsorption; Molecular Imprinting; Molecularly Imprinted Polymers; Nanoparticles; Polymerization; Polymers
PubMed: 33076552
DOI: 10.3390/molecules25204740 -
Topics in Current Chemistry (Cham) Mar 2020DNA nanotechnology, based on sequence-specific DNA recognition, could allow programmed self-assembly of sophisticated nanostructures with molecular precision. Extension... (Review)
Review
DNA nanotechnology, based on sequence-specific DNA recognition, could allow programmed self-assembly of sophisticated nanostructures with molecular precision. Extension of this technique to the preparation of broader types of nanomaterials would significantly improve nanofabrication technique to lower nanometer scale and even achieve single molecule operation. Using such exquisite DNA nanostructures as templates, chemical synthesis of polymer and inorganic nanomaterials could also be programmed with unprecedented accuracy and flexibility. This review summarizes recent advances in the synthesis and assembly of polymer and inorganic nanomaterials using DNA nanostructures as templates, and discusses the current challenges and future outlook of DNA templated nanotechnology.
Topics: Animals; DNA; Inorganic Chemicals; Liposomes; Nanostructures; Nanotechnology; Polymers
PubMed: 32146596
DOI: 10.1007/s41061-020-0292-x -
Molecules (Basel, Switzerland) Feb 2019Fiber structures with nanoscale diameters offer many fascinating features, such as excellent mechanical properties and high specific surface areas, making them... (Review)
Review
Fiber structures with nanoscale diameters offer many fascinating features, such as excellent mechanical properties and high specific surface areas, making them attractive for many applications. Among a variety of technologies for preparing nanofibers, electrospinning is rapidly evolving into a simple process, which is capable of forming diverse morphologies due to its flexibility, functionality, and simplicity. In such review, more emphasis is put on the construction of polymer nanofiber structures and their potential applications. Other issues of electrospinning device, mechanism, and prospects, are also discussed. Specifically, by carefully regulating the operating condition, modifying needle device, optimizing properties of the polymer solutions, some unique structures of core⁻shell, side-by-side, multilayer, hollow interior, and high porosity can be obtained. Taken together, these well-organized polymer nanofibers can be of great interest in biomedicine, nutrition, bioengineering, pharmaceutics, and healthcare applications.
Topics: Biocompatible Materials; Electrochemistry; Nanofibers; Particle Size; Polymers; Porosity
PubMed: 30813599
DOI: 10.3390/molecules24050834 -
Journal of the American Chemical Society Apr 2022Simple and efficient methods are a key consideration for small molecule and polymer syntheses. Direct arylation polymerization (DArP) is of increasing interest for...
Simple and efficient methods are a key consideration for small molecule and polymer syntheses. Direct arylation polymerization (DArP) is of increasing interest for preparing conjugated polymers as an effective approach compared to conventional cross-coupling polymerizations. As DArP sees broader utilization, advancements are needed to access materials with improved properties and different monomer structures and to improve the scalability of conjugated polymer synthesis. Presented herein are considerations for developing new methods of conjugated polymer synthesis from small molecule transformations, exploring how DArP has successfully used this approach, and presenting how emerging polymerization methodologies are developing similarly. While it is common to adapt small molecule methods to polymerizations, we demonstrate the ways in which information gained from studying polymerizations can inform and inspire greater advancements in small molecule transformations. This circular approach to organic synthetic method development underlines the value of collaboration between small molecule and polymer-based synthetic research groups.
Topics: Polymerization; Polymers
PubMed: 35380440
DOI: 10.1021/jacs.1c12455 -
Proceedings of the National Academy of... Apr 2023Biomolecular phase separation has emerged as an essential mechanism for cellular organization. How cells respond to environmental stimuli in a robust and sensitive...
Biomolecular phase separation has emerged as an essential mechanism for cellular organization. How cells respond to environmental stimuli in a robust and sensitive manner to build functional condensates at the proper time and location is only starting to be understood. Recently, lipid membranes have been recognized as an important regulatory center for biomolecular condensation. However, how the interplay between the phase behaviors of cellular membranes and surface biopolymers may contribute to the regulation of surface condensation remains to be elucidated. Using simulations and a mean-field theoretical model, we show that two key factors are the membrane's tendency to phase-separate and the surface polymer's ability to reorganize local membrane composition. Surface condensate forms with high sensitivity and selectivity in response to features of biopolymer when positive co-operativity is established between coupled growth of the condensate and local lipid domains. This effect relating the degree of membrane-surface polymer co-operativity and condensate property regulation is shown to be robust by different ways of tuning the co-operativity, such as varying membrane protein obstacle concentration, lipid composition, and the affinity between lipid and polymer. The general physical principle emerged from the current analysis may have implications in other biological processes and beyond.
Topics: Polymers; Cell Membrane; Membranes; Membrane Proteins; Lipids
PubMed: 37018196
DOI: 10.1073/pnas.2212516120 -
Molecules (Basel, Switzerland) May 2023With the increasing energy demand, oil is still an important fuel source worldwide. The chemical flooding process is used in petroleum engineering to increase the... (Review)
Review
With the increasing energy demand, oil is still an important fuel source worldwide. The chemical flooding process is used in petroleum engineering to increase the recovery of residual oil. As a promising enhanced oil-recovery technology, polymer flooding still faces some challenges in achieving this goal. The stability of a polymer solution is easily affected by the harsh reservoir conditions of high temperature and high salt, and the influence of the external environment such as high salinity, high valence cations, pH value, temperature and its own structure is highlighted. This article also involves the introduction of commonly used nanoparticles, whose unique properties are used to improve the performance of polymers under harsh conditions. The mechanism of nanoparticle improvement on polymer properties is discussed, that is, how the interaction between them improves the viscosity, shear stability, heat-resistance and salt-tolerant performance of the polymer. Nanoparticle-polymer fluids exhibit properties that they cannot exhibit by themselves. The positive effects of nanoparticle-polymer fluids on reducing interfacial tension and improving the wettability of reservoir rock in tertiary oil recovery are introduced, and the stability of nanoparticle-polymer fluid is described. While analyzing and evaluating the research on nanoparticle-polymer fluid, indicating the obstacles and challenges that still exist at this stage, future research work on nanoparticle-polymer fluid is proposed.
Topics: Polymers; Petroleum; Chemical Phenomena; Viscosity; Nanoparticles
PubMed: 37298805
DOI: 10.3390/molecules28114331 -
Physiological Research Oct 2016Self-organization in a polymer system appears when a balance is achieved between long-range repulsive and short-range attractive forces between the chemically different... (Review)
Review
Self-organization in a polymer system appears when a balance is achieved between long-range repulsive and short-range attractive forces between the chemically different building blocks. Block copolymers forming supramolecular assemblies in aqueous media represent materials which are extremely useful for the construction of drug delivery systems especially for cancer applications. Such formulations suppress unwanted physicochemical properties of the encapsulated drugs, modify biodistribution of the drugs towards targeted delivery into tissue of interest and allow triggered release of the active cargo. In this review, we focus on general principles of polymer selforganization in solution, phase separation in polymer systems (driven by external stimuli, especially by changes in temperature, pH, solvent change and light) and on effects of copolymer architecture on the self-assembly process.
Topics: Drug Delivery Systems; Hydrophobic and Hydrophilic Interactions; Nanoparticles; Polymers; Surface-Active Agents
PubMed: 27762583
DOI: 10.33549/physiolres.933419 -
Biomedicine & Pharmacotherapy =... May 2021Immunotherapy that boosts the body's immune system to treat local and distant metastatic tumors has offered a new treatment option for cancer. However, cancer... (Review)
Review
Immunotherapy that boosts the body's immune system to treat local and distant metastatic tumors has offered a new treatment option for cancer. However, cancer immunotherapy via systemic administration of immunotherapeutic agents often has two major issues of limited immune responses and potential immune-related adverse events in the clinic. Hydrogels, a class of three-dimensional network biomaterials with unique porous structures can achieve local delivery of drugs into tumors to trigger the antitumor immunity, resulting in amplified immunotherapy at lower dosages. In this review, we summarize the recent development of polymer-based hydrogels as drug release systems for local delivery of various immunotherapeutic agents for cancer immunotherapy. The constructions of polymer-based hydrogels and their local delivery of various drugs in tumors to achieve sole immunotherapy, and chemotherapy-, and phototherapy-combinational immunotherapy are introduced. Furthermore, a brief conclusion is given and existing challenges and further perspectives of polymer-based hydrogels for cancer immunotherapy are discussed.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Drug Delivery Systems; Drug Liberation; Humans; Hydrogels; Immunotherapy; Neoplasms; Phototherapy; Polymers
PubMed: 33571834
DOI: 10.1016/j.biopha.2021.111333 -
International Journal of Molecular... Sep 2022Using hybrid multi-particle collision dynamics (MPCD) and a molecular dynamics (MD) method, we investigate the effect of arms and shear flow on dynamical and structural...
Using hybrid multi-particle collision dynamics (MPCD) and a molecular dynamics (MD) method, we investigate the effect of arms and shear flow on dynamical and structural properties of the comb long-chain branched (LCB) polymer with dense arms. Firstly, we analyze dynamical properties of the LCB polymer by tracking the temporal changes on the end-to-end distance of both backbones and arms as well as the orientations of the backbone in the flow-gradient plane. Simultaneously, the rotation and tumbling behaviors with stable frequencies are observed. In other words, the LCB polymer undergoes a process of periodic stretched-folded-stretched state transition and rotation, whose period is obtained by fitting temporal changes on the orientation to a periodic function. In addition, the impact induced by random and fast motions of arms and the backbone will descend as the shear rate increases. By analyzing the period of rotation behavior of LCB polymers, we find that arms have a function in keeping the LCB polymer's motion stable. Meanwhile, we find that the rotation period of the LCB polymer is mainly determined by the conformational distribution and the non-shrinkable state of the structure along the velocity-gradient direction. Secondly, structural properties are numerically characterized by the average gyration tensor of the LCB polymer. The changes in gyration are in accordance with the LCB polymer rolling when varying the shear rate. By analyzing the alignment of the LCB polymer and comparing with its linear and star counterparts, we find that the LCB polymer with very long arms, like the corresponding linear chain, has a high speed to reach its configuration expansion limit in the flow direction. However, the comb polymer with shorter arms has stronger resistance on configuration expansion against the imposed flow field. Moreover, with increasing arm length, the comb polymer in shear flow follows change from linear-polymer-like to capsule-like behavior.
Topics: Molecular Conformation; Molecular Dynamics Simulation; Polymers; Rotation
PubMed: 36232591
DOI: 10.3390/ijms231911290