Solution-Phase Synthesis of KCl Nanocrystals Templated by PEO-PPO-PEO Triblock Copolymers Micelles

The current work introduces the synthesis of inorganic salt nano/micro-crystals during the reduction of hydrogen tetrachloroaurate(III) by Pluronic triblock copolymers (P123, PEO20-PPO70-PEO20). The morphologies and component were confirmed using an electron microscope with an electronic differential system (EDS), and the crystal structures were determined with X-ray diffraction (XRD). The morphologies highly depend on the concentrations of Pluronic and pH values. The mean size of the nanocrystal and hollow micro-crystal were controlled typically in the range of 32-150 nm (side length) and 1.4 μm, respectively. Different from the electrospray-ionization (EI) method, a model in which KCl forms a supersaturated solution in the micellar core of Pluronic is used to explain the formation process. This work provides the new insight that inorganic salt nanocrystals could be synthesized with the template of micelles in pure aqueous solutions.

Preparation and Characterization of Capsaicin Encapsulated Polymeric Micelles and Studies of Synergism with Nicotinic Acids as Potential Anticancer Nanomedicines

Background/Objective/Methods

Capsaicin micelles were prepared by the direct dissolution using the amphiphilic copolymer Pluronic P123 and advanced for substantially novel submicro-nanocytotoxicity.

Results

Superior cytotoxicity of capsaicin loaded nanomicelles vs. both the raw capsaicin and reference cisplatin in pancreatic PANC1, breast MCF7, colorectal resistant CACO2, skin A375, lung A549 and prostate PC3 cancer cell lines were delineated. Nicotinic acid (NA) derivative 39 (2-Amino IsoNA) had antiinflammatory potential but consistently lacked antiproliferation in MCF7, PANC1 and CACO2. Besides NA derivatives 8 (5-MethylNA) and 44 (6-AminoNA) exhibited lack of antiinflammation but had comparable antitumorigenesis potency to cisplatin in PANC1 cells. Though capsaicin loaded nanomicelles exerted pronounced antiinflammation (with IC50 value of 510 nM vs. Indomethacin's) in lipopolysacchride-induced inflammation of RAW247.6 macrophages; they lacked DPPH scavenging propensities. Free capsaicin proved more efficacious vs. its loaded nanocarriers to chemosensitize cytotoxicity of combinations with NAs 1(6-Hexyloxy Nicotinic Acid), 5(6-OctyloxyNA), 8(5-MethylNA), 12(6-Thien-2yl-NA), 13(5,6-DichloroNA) and 44(6-AminoNA) in CACO2, PANC1 and prostate PC3.

Conclusion

Capsaicin loaded nanomicelles proved more efficacious vs. free capsaicin to chemo-sensitize antiproliferation of cotreatments with NA derivatives, 1, 5, 8, 12, 13 and 44 (in skin A375), 1, 5, 8 and 12 (in breast MCF7), and 1, 5, 12 and 44 (in lung A549).

Recent advances in regenerative biomaterials

Nowadays, biomaterials have evolved from the inert supports or functional substitutes to the bioactive materials able to trigger or promote the regenerative potential of tissues. The interdisciplinary progress has broadened the definition of 'biomaterials', and a typical new insight is the concept of tissue induction biomaterials. The term 'regenerative biomaterials' and thus the contents of this article are relevant to yet beyond tissue induction biomaterials. This review summarizes the recent progress of medical materials including metals, ceramics, hydrogels, other polymers and bio-derived materials. As the application aspects are concerned, this article introduces regenerative biomaterials for bone and cartilage regeneration, cardiovascular repair, 3D bioprinting, wound healing and medical cosmetology. Cell-biomaterial interactions are highlighted. Since the global pandemic of coronavirus disease 2019, the review particularly mentions biomaterials for public health emergency. In the last section, perspectives are suggested: (i) creation of new materials is the source of innovation; (ii) modification of existing materials is an effective strategy for performance improvement; (iii) biomaterial degradation and tissue regeneration are required to be harmonious with each other; (iv) host responses can significantly influence the clinical outcomes; (v) the long-term outcomes should be paid more attention to; (vi) the noninvasive approaches for monitoring in vivo dynamic evolution are required to be developed; (vii) public health emergencies call for more research and development of biomaterials; and (viii) clinical translation needs to be pushed forward in a full-chain way. In the future, more new insights are expected to be shed into the brilliant field-regenerative biomaterials.

Utilizing an aggregate forming microenvironment sensitive coumarin–cholesterol conjugate as a sensor of pluronic organization and micro-polarity

A new fluorescent cholesterol molecular probe, 3-acetyl-7-(diethylamino)-2H-chromen-2-one attached cholesterol (Cum–Chl), has recently been introduced as a reporter of micro-heterogeneous media.

Tumor regression achieved by encapsulating a moderately soluble drug into a polymeric thermogel

For cancer chemotherapy, a tumor regression without any surgical resection and severe side effects is greatly preferred to merely slowing down the growth of tumors. Here, we report a formulation composed of irinotecan (IRN) and poly(D,L-lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(D,L-lactide-co-glycolide) (PLGA-PEG-PLGA). IRN is a clinically used antitumor drug with active and inactive chemical forms in equilibrium, and the major form at physiological conditions is inactive but still has side effects. The aqueous solution of the PLGA-PEG-PLGA is a sol at room temperature and physically gels at body temperature, forming a thermogel. We successfully mixed this moderately soluble drug into the amphiphilic copolymer aqueous solution for the first time. The mixture was subcutaneously injected into nude mice with xenografted SW620 human colon tumors. Excellent in vivo antitumor efficacy was observed in the group that received the IRN-loaded thermogel. The tumor was significantly regressed after being treated with the IRN/thermogel, and the side effects (blood toxicity and body weight decrease) were very mild. These results might be attributed to the ideal sustained release profile and period of release of the drug from the thermogel and to the significant enhancement of the fraction of the active form of the drug by the thermogel.

Cell-material interactions revealed via material techniques of surface patterning

Cell-material interactions constitute a key fundamental topic in biomaterials study. Various cell cues and matrix cues as well as soluble factors regulate cell behaviors on materials. These factors are coupled with each other as usual, and thus it is very difficult to unambiguously elucidate the role of each regulator. The recently developed material techniques of surface patterning afford unique ways to reveal the underlying science. This paper reviews the pertinent material techniques to fabricate patterns of microscale and nanoscale resolutions, and corresponding cell studies. Some issues are emphasized, such as cell localization on patterned surfaces of chemical contrast, and effects of cell shape, cell size, cell-cell contact, and seeding density on differentiation of stem cells. Material cues to regulate cell adhesion, cell differentiation and other cell events are further summed up. Effects of some physical properties, such as surface topography and matrix stiffness, on cell behaviors are also discussed; nanoscaled features of substrate surfaces to regulate cell fate are summarized as well. The pertinent work sheds new insight into the cell-material interactions, and is stimulating for biomaterial design in regenerative medicine, tissue engineering, and high-throughput detection, diagnosis, and drug screening.