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Molecules (Basel, Switzerland) Sep 2020Cancer represents one of the most dangerous diseases, with 1.8 million deaths worldwide. Despite remarkable advances in conventional therapies, these treatments are not... (Review)
Review
Cancer represents one of the most dangerous diseases, with 1.8 million deaths worldwide. Despite remarkable advances in conventional therapies, these treatments are not effective to completely eradicate cancer. Nanotechnology offers potential cancer treatment based on formulations of several nanoparticles (NPs). Liposomes and polymeric nanoparticle are the most investigated and effective drug delivery systems (DDS) for cancer treatment. Liposomes represent potential DDS due to their distinct properties, including high-drug entrapment efficacy, biocompatibility, low cost, and scalability. However, their use is restricted by susceptibility to lipid peroxidation, instability, burst release of drugs, and the limited surface modification. Similarly, polymeric nanoparticles show several chemical modifications with polymers, good stability, and controlled release, but their drawbacks for biological applications include limited drug loading, polymer toxicity, and difficulties in scaling up. Therefore, polymeric nanoparticles and liposomes are combined to form polymer-lipid hybrid nanoparticles (PLHNPs), with the positive attributes of both components such as high biocompatibility and stability, improved drug payload, controlled drug release, longer circulation time, and superior in vivo efficacy. In this review, we have focused on the prominent strategies used to develop tumor targeting PLHNPs and discuss their advantages and unique properties contributing to an ideal DDS.
Topics: Animals; Humans; Lipids; Molecular Targeted Therapy; Nanoparticles; Neoplasms; Polymers
PubMed: 32977707
DOI: 10.3390/molecules25194377 -
Medecine Sciences : M/S Jan 2017Implants for controlled drug delivery can be very helpful to improve the therapeutic efficacy of a medical treatment, and at the same time reduce the risk of toxic side... (Review)
Review
Implants for controlled drug delivery can be very helpful to improve the therapeutic efficacy of a medical treatment, and at the same time reduce the risk of toxic side effects. In this article, four different strategies are exemplarily presented: hybrid bone substitutes combining hydroxyapatite and chitosan hydrogels; vascular stents coated with a bio-inspired polymer; cochlear implants for local dexamethasone delivery; and in-situ forming implants for periodontitis treatment. But this is only a restricted selection, and numerous other approaches and applications based on implants releasing a drug (or a combination of drugs) exist. Compared to conventional implants or pharmaceutical dosage forms, they might offer decisive advantages.
Topics: Animals; Cochlear Implants; Dental Implants; Drug Delivery Systems; Drug Implants; Drug-Eluting Stents; Graft Occlusion, Vascular; Humans; Periodontium; Polymers
PubMed: 28120753
DOI: 10.1051/medsci/20173301006 -
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 -
ACS Sensors Jan 2022Degradable polymers are widely used in the biomedical fields due to non-toxicity and great biocompatibility and biodegradability, and it is crucial to understand how...
Degradable polymers are widely used in the biomedical fields due to non-toxicity and great biocompatibility and biodegradability, and it is crucial to understand how they degrade. These polymers are exposed to various biochemical media in medical practice. Hence, it is important to precisely follow the degradation of the polymer in real time. In this study, we made use of diamond magnetometry for the first time to track polymer degradation with nanoscale precision. The method is based on a fluorescent defect in nanodiamonds, which changes its optical properties based on its magnetic surrounding. Since optical signals can be read out more sensitively than magnetic signals, this method allows unprecedented sensitivity. We used a specific mode of diamond magnetometry called relaxometry or T1 measurements. These are sensitive to magnetic noise and thus can detect paramagnetic species (gadolinium in this case). Nanodiamonds were incorporated into polylactic acid (PLA) films and PLA nanoparticles in order to follow polymer degradation. However, in principle, they can be incorporated into other polymers too. We found that T1 constants decreased gradually with the erosion of the film exposed to an alkaline condition. In addition, the mobility of nanodiamonds increased, which allows us to estimate polymer viscosity. The degradation rates obtained using this approach were in good agreement with data obtained by quartz crystal microbalance, Fourier-transform infrared spectroscopy, and atomic force microscopy.
Topics: Diamond; Magnetometry; Nanodiamonds; Polyesters; Polymers
PubMed: 34982542
DOI: 10.1021/acssensors.1c01782 -
Current Opinion in Biotechnology Jun 2023The urge to discover and develop new technologies for closing the plastic carbon cycle is motivating industries, governments, and academia to work closely together to... (Review)
Review
The urge to discover and develop new technologies for closing the plastic carbon cycle is motivating industries, governments, and academia to work closely together to find suitable solutions in a timely manner. In this review article, a combination of uprising breakthrough technologies is presented highlighting their potential and complementarity to be integrated one with the other, therefore providing a potential solution to efficiently solve the plastics problem. First, modern approaches for bio-exploration and engineering of polymer-active enzymes are presented to degrade polymers into valuable building blocks. Special focus is placed on the recovery of components from multilayered materials since these complex materials can only be recycled insufficiently or not at all by existing technologies. Then, the potential of microbes and enzymes for resynthesis of polymers and reuse of building blocks is summarized and discussed. Finally, examples for improvement of the bio-based content and enzymatic degradability and future perspectives are given.
Topics: Plastics; Polymers; Recycling
PubMed: 37058877
DOI: 10.1016/j.copbio.2023.102938 -
International Journal of Molecular... Dec 2023Chitosan is a polymer of natural origins that possesses many favourable properties [...].
Chitosan is a polymer of natural origins that possesses many favourable properties [...].
Topics: Chitosan; Polymers
PubMed: 38203726
DOI: 10.3390/ijms25010554 -
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 -
Molecules (Basel, Switzerland) Nov 2022Polyhydroxyalkanoate (PHA), a biodegradable polymer obtained from microorganisms and plants, have been widely used in biomedical applications and devices, such as... (Review)
Review
Polyhydroxyalkanoate (PHA), a biodegradable polymer obtained from microorganisms and plants, have been widely used in biomedical applications and devices, such as sutures, cardiac valves, bone scaffold, and drug delivery of compounds with pharmaceutical interests, as well as in food packaging. This review focuses on the use of polyhydroxyalkanoates beyond the most common uses, aiming to inform about the potential uses of the biopolymer as a biosensor, cosmetics, drug delivery, flame retardancy, and electrospinning, among other interesting uses. The novel applications are based on the production and composition of the polymer, which can be modified by genetic engineering, a semi-synthetic approach, by changing feeding carbon sources and/or supplement addition, among others. The future of PHA is promising, and despite its production costs being higher than petroleum-based plastics, tools given by synthetic biology, bioinformatics, and machine learning, among others, have allowed for great production yields, monomer and polymer functionalization, stability, and versatility, a key feature to increase the uses of this interesting family of polymers.
Topics: Polyhydroxyalkanoates; Biopolymers; Drug Delivery Systems; Petroleum; Food Packaging
PubMed: 36500442
DOI: 10.3390/molecules27238351 -
Molecules (Basel, Switzerland) Mar 2016The polyfunctional nature of chitosan enables its application as a polymer ligand not only for the recovery, separation, and concentration of metal ions, but for the... (Review)
Review
The polyfunctional nature of chitosan enables its application as a polymer ligand not only for the recovery, separation, and concentration of metal ions, but for the fabrication of a wide spectrum of functional materials. Although unmodified chitosan itself is the unique cationic polysaccharide with very good complexing properties toward numerous metal ions, its sorption capacity and selectivity can be sufficiently increased and turned via chemical modification to meet requirements of the specific applications. In this review, which covers results of the last decade, we demonstrate how different strategies of chitosan chemical modification effect metal ions binding by O-, N-, S-, and P-containing chitosan derivatives, and which mechanisms are involved in binding of metal cation and anions by chitosan derivatives.
Topics: Adsorption; Chitosan; Cross-Linking Reagents; Ligands; Metals; Molecular Structure; Polymers
PubMed: 26978343
DOI: 10.3390/molecules21030330 -
Accounts of Chemical Research Jun 2022Poor waste management and unchecked consumption underpin our current paradigm of plastics use, which is demonstrably unsustainable in the long term. Nonetheless, the...
Poor waste management and unchecked consumption underpin our current paradigm of plastics use, which is demonstrably unsustainable in the long term. Nonetheless, the utility and versatility of plastics suggest that the notion of a plastic-free society is also unsustainable. Responses to this conundrum are increasing, and among these are research efforts focused on the development of more sustainable plastics. This Account, written by trained chemists, reflects an academic research journey culminating in an appreciation of the importance of improving and enabling the overarching systems that plastics exist within. Our primary initial focus was on catalyst development because catalysts are key drivers of sustainability by improving the efficiency and ease of polymerization. Metal catalysts ranging in ligand structure and the incorporated metal(s) were developed for the preparation of traditional polyesters such as poly(lactic acid) and polycaprolactone. The central themes in these works were stereocontrol (tacticity), efficiency (polymerization rate), and versatility (monomer scope). Alongside insights gained by systematically varying catalyst structure came impressive results gained through collaboration, including the remarkably high activity of novel heterometallic zinc catalysts toward various cyclic esters.This catalysis work was complemented by and slowly transitioned to a focus on polymer functionality and monomer design. Several fundamental studies focus on polymer topology, specifically star-shaped polyesters, tuned arm number, length, and tacticity. These reports feature emphases on the end of life (solvolysis) and physical properties of polymers, which were increasingly important themes as work shifted toward new methods of incorporating functionality in polymers produced by ring-opening polymerization. Three key highlights demonstrate this shift: the first two rely upon the exploitation of olefin metathesis (cross- and ring-closing) to functionalize polyesters or polyethers, and the third involves the manipulation of ring-opening polymerization equilibrium to enable selective monomer recovery from a polyester. Our foundational work on 1,3-dioxolan-4-one (DOX) monomers is then discussed because this emerging class of molecules offers a distinct synthetic pathway toward functional polyesters, both conventional and novel. With this DOX framework, polyesters that are usually challenging to synthesize (e.g., poly(mandelic acid)) are accessible because polymerization is driven by the concomitant, controlled extrusion of small molecules (acetone or formaldehyde).After these polyester-focused highlights, the foundation of our ongoing work is presented, namely, that polymer sustainability must be viewed from a systems-level perspective, including economic and social components alongside the environmental considerations. Material design must be driven by practice, and we have to involve key players in academia, industry, and government in a concerted effort to enable positive and robust change. The key goal is to develop sustainable systems that retain plastics in their highest value state for as long as possible by designing materials and products for a particular (and assured) end-of-life fate, whether that be reuse, recycling, (bio)degradation, or energy recovery.
Topics: Metals; Plastics; Polyesters; Polymerization; Polymers
PubMed: 35579567
DOI: 10.1021/acs.accounts.2c00134