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Nanomaterials in Chemotherapy
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
P. K. Hashim, Anjaneyulu Dirisala
Polymers are large molecular weight substances consisting of repeating monomeric units that are connected via covalent bonds. Nature derived polymers such as polysaccharides (e.g., cellulose, hyaluronic acid, etc.) and synthetic polymers such as poly(glycolic acid), poly(lactic acid), poly(caprolactone), and polydioxanone have become an inevitable component of DDSs. With the advancements in the field of polymers, many efficient methods of polymer synthesis are now available. Careful selection of monomeric motifs can produce polymers having different structures (linear, branched, and dendritic), configurations (copolymers), and properties (hydrophilic and hydrophobic), as shown in Figure 8.7. Some specific type of polymers such as amphiphilic block copolymers is widely utilized for constructing drug carriers in biomedical applications. Hydrophilic/hydrophobic small molecule drugs, nucleic acids, peptides, and proteins can be loaded into polymeric nanocarriers (e.g., micelles and polymersomes), where the designed carriers sustain in the bloodstream and accumulate in a diseased site followed by cellular internalization and drug release [127, 128].
Application of Bioresponsive Polymers in Drug Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Manisha Lalan, Deepti Jani, Pratiksha Trivedi, Deepa H. Patel
A copolymer of NIPAAm and acrylic acid was developed which had both pH and temperature sensitivity for use in the preparation of matrix drug delivery system. The drug was admixed physically with the developed copolymer. Although this was, a matrix system but it behaved very similar to enteric coating. The system remained intact and insoluble at acidic pH and gradually dissolving at intestinal pH. The developed formulation did not release rapidly in intestine in contrast to enteric-coated tablets, but gave sustained release of drug over an extended period of time. The rate of drug release directly correlated with the amount of acrylic acid [31].
Polymers as Conditioning Agents for Hair and Skin
Published in Randy Schueller, Perry Romanowski, Conditioning Agents for Hair and Skin, 2020
Many of the objectionable properties of PVP homopolymer were overcome by the introduction of PVP random copolymers. A random copolymer tends to have properties which are intermediate between the properties of the homopolymers which would be formed by polymerizing the monomers separately. Thus, a polar hygroscopic homopolymer can be rendered more moisture resistant by introduction of a nonpolar comonomer (20).
Synthetic biodegradable polyesters for implantable controlled-release devices
Published in Expert Opinion on Drug Delivery, 2022
Jinal U. Pothupitiya, Christy Zheng, W. Mark Saltzman
PLGA is generated by the copolymerization of LA and GA. The copolymer exhibits far superior properties compared to their respective homopolymers and is one of the most extensively used polyesters in biomedical applications [76]. Since the individual homopolymers have different degradation rates, solubilities, and physical properties, the properties of the copolymer can be manipulated by changing the ratio of glycolic to lactic acid monomers [102,129]. A higher GA content within PLGA leads to a lower degree of crystallinity and a higher rate of hydrolysis [130]. It has been reported that PLGA containing 50% of LA displays the fastest degradation rates, where the degradation times of 50:50 PLGA, 75:25 PLGA, and 85:15 PLGA are 1–2 months, 4–5 months, and 5–6 months, respectively [76]. All PLGA copolymers display Tg values above 37°C, indicating a rigid structure suitable for implant manufacturing. Lastly, PLGA can be processed into a wide variety of shapes and sizes [72,131] due to its solubility in common organic solvents such as tetrahydrofuran, acetone, and ethyl acetate [129].
Novel polysaccharide building hybrid nanoparticles: remodelling TAMs to target ERα-positive breast cancer
Published in Journal of Drug Targeting, 2022
Chunjing Guo, Yanguo Su, Bingjie Wang, Qiang Chen, Huimin Guo, Ming Kong, Daquan Chen
In this work, two kinds of amphiphilic copolymers were designed. On the one hand, folic acid (FA) was chosen as a hydrophobic fragment, because FA can target folate receptors on the surface of tumour cells and FRβ on the surface of M2-TAMs. Mannose (Man) can especially combine with CD206 on the surface of M2-TAMs, which was used to link FA and oHA. Hence, the oligomeric hyaluronic acid-mannose-folic acid (oHA-Man-FA, HMF) was designed. On the other hand, GSH-sensitive dithiodipropionic acid (S-S) was selected to link APS with immune-potentiating effect and paeonol (Pae), as the hydrophobic end. Hence, astragalus polysaccharide-dithiodipropionic acid-paeonol (APS-SS-Pae, ASP) was synthesised. HMF and ASP are used to prepare hybrid nanoparticles (HP-NPs, a kind of hybrid micelles) by dialysis, which are used to co-encapsulate PTX and Bai. As shown in Figure 1, HP-NPs are used to achieve the combination of chemotherapy and immunotherapy. We believe that HP-NPs have good clinical application prospects in breast cancer treatment.
Development of stimuli-responsive intelligent polymer micelles for the delivery of doxorubicin
Published in Journal of Drug Targeting, 2020
Fan Yang, Jiangkang Xu, Manfei Fu, Jianbo Ji, Liqun Chi, Guangxi Zhai
Currently, the development of biocompatible and biodegradable stimuli-responsive copolymers is one of the focuses of intelligent PMs. However, the clinical applications of many copolymers face many problems and challenges. Very few biological materials can be approved for testing in clinical trails, and currently, only about nine drug-loaded PMs have been studied in clinical. Therefore, the main problem that currently plagues the application of PMs is that its clinical translation and target therapeutic effects are far from impressive satisfaction [13]. In addition, the structure mechanisms of physiological environment in the human body and the tumour microenvironment are very complicated, and the interaction mechanism between DOX-loaded intelligent PMs and the tumour cells are difficult to accurately evaluate. Moreover, the micelles also have many difficulties in transporting drugs, and the problem of drug leakage in blood circulation is always a headache problem for their applications. When the human body suffers other special diseases such as oxidative stress and inflammation, some non-cancerous tissues exhibit the physicochemical properties similar to cancerous tissues, which may cause more adverse side effects [71,177,178].