[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

https://cyberleninka.org/article/n/933162.pdf

Hydrogels in drug delivery: progress and challenges

Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

https://www.farm.ucl.ac.be/Full-texts-FARM/Danhier-2010-2.pdf

To exploit the tumor microenvironment: Passive and active tumor targeting of nanocarriers for anti-cancer drug delivery

/pdf/degradable-controlled-release-polymers-and-polymeric-1y322ha58z.pdf

Degradable Controlled-Release Polymers and Polymeric Nanoparticles: Mechanisms of Controlling Drug Release

Biodegradable polymers/oligomers based on epsilon-caprolactone (CL) were end-functionalized by a cholesteryl moiety. The functionalized polymers/oligomers, Chol-(CL)n, were synthesized through ring-opening polymerization initiated by cholesterol with a hydroxyl group. The chemical structure of end-functionalized polymers/oligomers was confirmed by FT-IR and 1H-NMR. The molecular weight of the functionalized polymer/oligomer increases with decreasing feed ratio of the initiator cholesterol to the monomer CL. Incorporation of the cholesteryl moiety to the polymer chain results in liquid crystallinity for the resultant oligomers when their molecular chains are not very long. The enzymatic degradation of the functionalized polymers/oligomers was investigated. The microsphere drug-delivery system of a functionalized oligomer was fabricated and its drug release properties were evaluated. The cell-culture experiment indicates the incorporation of cholesteryl moiety to the polymer chain results in improved cell proliferation.

Studies on functionalization of poly(epsilon-caprolactone) by a cholesteryl moiety.

Selective amplification of reactive oxygen species (ROS) generation in tumor cells has been recognized as an effective strategy for cancer therapy. However, an abnormal tumor metabolism, especially the mitochondrial glutaminolysis, could promote tumor cells to generate high levels of antioxidants (e.g., glutathione) to evade ROS-induced damage. Here, we developed a tumor-targeted nanoparticle (NP) platform for effective breast cancer therapy via combining inhibition of mitochondrial glutaminolysis and chemodynamic therapy (CDT). This NP platform is composed of bovine serum albumin (BSA), ferrocene, and purpurin. After surface decoration with a tumor-targeting aptamer and then intravenous administration, this NP platform could target tumor cells and release ferrocene to catalyze hydrogen peroxide (H2O2) into the hydroxyl radical (·OH) for CDT. More importantly, purpurin could inhibit mitochondrial glutaminolysis to concurrently prevent the nutrient supply for tumor cells and disrupt intracellular redox homeostasis for enhanced CDT, ultimately leading to the combinational inhibition of tumor growth.

Nanoparticle-Mediated Inhibition of Mitochondrial Glutaminolysis to Amplify Oxidative Stress for Combination Cancer Therapy.

A facile strategy to perform the boron coordination reaction on a template of nanofibers is developed. Peptides with phenylboronic acid tails (peptidyl boronic acids) are designed and prepared as building blocks that can self-assemble into nanofibers. After the addition of vicinal diol structural motifs to the self-assembling system, matrix-assisted laser desorption-ionization time-of-flight mass spectrometry indicates that the boron coordination reaction occurs on the template of nanofibers, which results in the increase of the width and roughness of the nanofibers as demonstrated by transmission electron microscopy and atomic force microscopy measurements. Because the surface-bound vicinal diol structural motifs have an ability to form hydrogen bonds with the peptide segments on the nanofibers, which restrain and disturb the hydrogen-bonding interaction among the nanofibers, the network structure formed based on the entanglement of nanofibers via hydrogen-bonding interaction is destroyed, which leads to a gel-sol transition. The novel concept of post-self-assembly modification demonstrated here could lead to a new technique for using self-assembled nanostructures in the emerging fields of nanoscience and nanotechnology.

Facile construction of nanofibers as a functional template for surface boron coordination reaction.

The destabilization effect of a hydrophilic polymer, poly-α,β-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA), and an amphiphilic polymer, PHEA-g-poly(2,2-dimethyltrimethylene carbonate) (PHEA-g-PDTC), on phosphatidylcholine vesicles has been investigated. The hydrophilic polymer PHEA has a strong destabilizing effect on the liposomes and induces immediate vesicular membrane leakage and aggregation, while the destabilizing effect of the amphiphilic polymer PHEA-g-PDTC is weaker. The in situ observation on shape transformations of a vesicle indicates that the addition of PHEA increases the amplitudes of fluctuations of the vesicle membrane, finally leading to the burst of the vesicle. The existence of hydrogen bonding between the polymers and the liposome membranes is mainly responsible for inducing the destabilization. The molecular structure of the polymers, such as the stiffness of the polymer backbone and the spacer connecting the hydroxyl group with the backbone, greatly affects the interaction between the polymers and the vesicles.

Destabilization of liposomes by uncharged hydrophilic and amphiphilic polymers

A strategy for in situ chemical gelation of poly(N-isopropylacrylamide-co-glycidyl methacrylate)/polyethylenimine (P(NIPAAm-co-GMA)/PEI) polymers has been demonstrated. Two kinds of P(NIPAAm-co-GMA) with epoxy pendant groups were prepared. When the solution of P(NIPAAm-co-GMA) was mixed with branched polyethylenimine (PEI, Mw 800), the cross-linking between the epoxy functional groups and amines, a type of nucleophilic substitution reaction occurred. The corresponding gelation process was confirmed via rheology. The in situ formed hydrogels were studied via scanning electric microscopy (SEM) and the equilibrium swelling ratio, swelling kinetics, and temperature response kinetics were examined. The strategy described here presents a potential alternative to the traditional synthesis techniques for the in situ formation of thermosensitive hydrogels.

Si-Xue Cheng

Papers

Studies on functionalization of poly(epsilon-caprolactone) by a cholesteryl moiety.

Nanoparticle-Mediated Inhibition of Mitochondrial Glutaminolysis to Amplify Oxidative Stress for Combination Cancer Therapy.

Facile construction of nanofibers as a functional template for surface boron coordination reaction.

Destabilization of liposomes by uncharged hydrophilic and amphiphilic polymers

In situ formation of thermosensitive P(NIPAAm-co-GMA)/PEI hydrogels