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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].
Virus-Based Nanocarriers for Targeted Drug Delivery
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Semra Akgönüllü, Monireh Bakhshpour, Yeşeren Saylan, Adil Denizli
Micelles come together to create a nanosized core or shell structure in the aqueous environment. The properties of micelles depend on amphiphilic block copolymers. The hydrophobic core part acts as a reservoir for especially hydrophobic drugs. The hydrophilic shell part stabilises the hydrophobic core to make the particle a suitable candidate and make polymers water soluble (Adams et al. 2003). Polymeric micelles obtained by the block copolymers’ organisation are mostly studied in drug delivery. Drug loading into polymeric micelles is achieved by physical encapsulation or covalent binding (Cho et al. 2008).
Phytoconstituent-Loaded Nanomedicines for Arthritis Management
Published in Mahfoozur Rahman, Sarwar Beg, Mazin A. Zamzami, Hani Choudhry, Aftab Ahmad, Khalid S. Alharbi, Biomarkers as Targeted Herbal Drug Discovery, 2022
Syed Salman Ali, Snigdha Bhardwaj, Najam Ali Khan, Syed Sarim Imam, Chandra Kala
The active principle remains entangled within the core of the micellar structure and transported at concentrations with an increase in the intrinsic water-solbility profile. In the micellar structure, the hydrogen bonding generally takes place with the aqueous surroundings in the hydrophilic blocks which develops an intact covering layer around the micellar core. This provides nice protection to the hydrophobic contents of the core against chemical reactions such as hydrolysis and enzymatic degradation. Amphiphilic block copolymers can be easily changed their chemical composition of compounds, structural block length ration and molecular weight (total) which allows monitoring of surface morphology 9 (size, shape, and surface charge, etc.), ofthe micelles, represent extraordinary feature for drug delivery applications. Surface charge modification facilitates the functionalization of block copolymers with crosslinking groups (ligands), during micellar formation, resulting in high stability and site-selectivity of formed structure (Costas et al., 2006).
Phenylboronic ester-modified polymeric nanoparticles for promoting TRP2 peptide antigen delivery in cancer immunotherapy
Published in Drug Delivery, 2022
Qiyan Wang, Zhipeng Dong, Fangning Lou, Yunxue Yin, Jiahao Zhang, Hanning Wen, Tao Lu, Yue Wang
The polymer, as an optimized carrier, provide a biomedical platform for encapsulating tumor antigen and protecting them from degradation, which can accurately deliver sufficient doses of antigen to target the strongest antigen presenting cell, dendritic cell (DC). Based on our previous work, we here mainly extend the series of block copolymers with different molecular weight for optimization to achieve enhanced immunogenicity. The nanovaccine are self-assembled to form a core-shell structure including an anion copolymer (PAsp-g-PBE) in the inner core to encapsulate the tumor-associated antigen peptide derived from TRP2 (SVYDFFVWL, an MHC-I restricted epitope) (Kakwere et al., 2017; Zeng et al., 2017; Zhang et al., 2017) through electrostatic interaction, and hydrophilic PEG outer layer to prolong blood circulation time. Through optimization, the candidate carrier PEG-b-PAsp-g-PBE with the proper block can transport TRP2 peptide to APC in lymph nodes efficiently and then loses its PBE side chains, leading to release of the preloaded TRP2 under the high level of ROS in DC cells. Also by the means of PEG-b-PAsp-g-PBE carrier, TRP2 tumor antigen is able to enhance cross-presentation, which facilitates endogenous antigen presenting via MHC-I for a cytotoxic T cell responses. Moreover, TRP2 tumor antigen could be accumulated in the draining lymph nodes for DC long-term antigen presentation with PEG-b-PAsp-g-PBE delivery.
Janus nanoparticles: an efficient intelligent modern nanostructure for eradicating cancer
Published in Drug Metabolism Reviews, 2021
Farshid Gheisari, Mostafa Shafiee, Milad Abbasi, Ali Jangjou, Peyman Izadpanah, Ahmad Vaez, Ali Mohammad Amani
The self-assembly process of block copolymers in bulk density is indeed a versatile technique that can be used for several different forms of polymers. Owing to the heterogeneity of various polymers, block copolymers in the bulk mass demonstrate microphase separation compositions. The heat and mass transfer explanation of the formation mechanism of the polymer couple can be provided through the Flory–Huggins formula (Walther and Muller 2013). Flory–Huggins solution principle provides a crystal structure framework of the fluid dynamics of polymer fluids which take into consideration the considerable differences in molecular dimensions in adjusting the ordinary concept for the entropy of blending. The existence of such nanoparticles is defined not just by the Flory–Huggins activity coefficient between such block copolymers, but also with the weight percentage of the level of polymerization. The development stage graphs of the diblock copolymers seem to be experimentally and theoretically well studied (Yang 2012). Typically, many architectural changes can be identified by an increment in mass proportion over one block between 0 and 50% in volume proportion – beginning from its blended stage, through the spherical phase, the cylindrical phase, the gyroid phase, and eventually finishing within the lamellar phase (Figure 4).
Addressing the challenges to increase the efficiency of translating nanomedicine formulations to patients
Published in Expert Opinion on Drug Discovery, 2021
Sourav Bhattacharjee, David J. Brayden
Polymeric micelles have a hydrophobic core within a hydrophilic corona and offer loading possibilities for both hydrophilic and hydrophobic molecules. The polymeric constituent is usually a di-block or tri-block copolymer, where at least one of the blocks is hydrophilic and forms the outer layer. The hydrophobic block, on the other hand, forms the core, which in turn is stabilized by a range of hydrophobic and ionic bonds or complexation with metal ions. A wide range of polymeric blocks can be used to form cores with different hydrophilicity, such as polypropylene oxide (Pluronics®) [104], polyaspartic acid [105], polylactic acid [106], poly-ε-caprolactone (PCL) [107], and poly(β-benzyl-L-aspartate) [108]. Some of these polymers (e.g., PCL) are biodegradable and can be used to develop sustained-release formulations.