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Abstract: Biomimetic acryloyloxyethyl phosphorylcholine (APC) was used to react with generation 5 poly(amido amine) (PAMAM) dendrimers (G5) via the Michael addition reaction between primary amino group of PAMAM dendrimers and acrylic functional group of APC. FTIR and 1H NMR confirmed the success of surface modification of G5. The primary amino and phosphorylcholine (PC) group numbers of the surface engineered PAMAM dendrimers (G5-PC) were calculated to be 56 and 50 via 1H NMR and potentiometric titration. Cell viability and cell morphology studies indicated that biomimetic phosphorylcholine surface engineering successfully lowered the cytotoxicity of G5 PAMAM dendrimers. The hydrophobic interior of G5-PC was used to incorporate anti-cancer drug Adriamycin (ADR) and the G5-PC showed sustained releasing behavior for ADR. Cell morphology and viability tests indicated that the drug-loaded G5-PC conjugate could effectively enter the cancer cells and inhibit the growth of cancer cells. Biomimetic phosphorylcholine surface engineered PAMAM dendrimers with lowered cytotoxicity and high cellular penetrating ability showed great potential for the biomedical applications as nanocarrier system. [Copyright &y& Elsevier]

Silica nanotubes were prepared using the gelatin nanofibers as novel sacrificed template via a sol-gel route with a subsequent calcination process. FT-IR spectrum showed that the siloxane bonds (Si-O-Si) were involved in the silica nanotubes. SEM observations showed that the silica nanotubes had an average diameter of 742 ± 82 nm with a hollow cavity of 513 ± 68 nm. The formation of the tubular hollow structure was attributed to the removal of gelatin template. After soaked in the solution of tetracycline hydrochloride (TH, one of the representative antibiotics) as model drug, the silica nanotubes favored the adsorption of TH with the loading efficiency of 38%. A sustained release behavior of TH was observed as the TH-loaded silica nanotubes were soaked in the phosphate buffer saline. The released TH was biologically active to strongly inhibit the growth of bacterial E. coli . [ABSTRACT FROM AUTHOR]

This paper presents a facile and low-cost strategy for fabrication lysozyme-loaded mesoporous silica nanotubes (MSNTs) by using silk fibroin (SF) nanofiber templates. The "top-down method" was adopted to dissolve degummed silk in CaCl2/ formic acid (FA) solvent, and the solution containing SF nanofibrils was used for electrospinning to prepare SF nanofiber templates. As SF contains a large number of -OH, -NH2 and -COOH groups, the silica layer could be easily formed on its surface by the Söber sol-gel method without adding any surfactant or coupling agent. After calcination, the MSNTs were obtained with inner diameters about 200 nm, the wall thickness ranges from 37 ± 2 nm to 66 ± 3 nm and the Brunauer–Emmett–Teller (BET) specific surface area was up to 200.48 m2/g, the pore volume was 1.109 cm3/g. By loading lysozyme, the MSNTs exhibited relatively high drug encapsulation efficiency up to 31.82% and an excellent long-term sustained release in 360 h (15 days). These results suggest that the MSNTs with the hierarchical structure of mesoporous and macroporous will be a promising carrier for applications in biomacromolecular drug delivery systems. [ABSTRACT FROM AUTHOR]

Nano-sized amorphous calcium carbonate (ACC) have a great potential for drug transport and drug delivery because of their high drug loading capacity, excellent biocompatibility and biodegradability. However, ACC is the thermodynamically least stable phase of calcium carbonate, and such thermal metastability often transforms it into more stable vaterite or calcite phases, so the inhibition of the phase transformation of ACC is of great significance for its application in drug delivery systems. Herein, phosphate as a morphology controlling additive was introduced to stabilize the metastable ACC. The results showed that the composite nanoparticles (named here the ACCP) with narrow size distribution located at approximately 128 nm (measured by dynamic light scattering) were obtained, when Ca2+ concentration and C/P were 10 mM and 7/3 respectively, prepared at 30 °C for 10 min. The powdered X-ray diffraction (XRD) results showed that phosphate has an excellent ability to stabilize ACC, and even after storage for 60 days at room temperature, the structure of ACCP remains amorphous. The in vitro drug release tests showed that ACCP nanoparticles had a high curcumin (Cur) loading capacity and a sustained drug release property. Moreover, the 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) radical scavenging activity assay showed that ACCP-encapsulating strategy could effectively prevent the decomposition of Cur. In vitro cytotoxicity tests demonstrated that the resultants have excellent biocompatibility. Therefore, the as-prepared ACCP nanoparticles are promising for drug delivery applications. • The nano-sized ACCP particles were successful prepared using phosphate as a stabilizer. • Cur-loaded ACCP shows favorable Cur release properties. • The ACCP-Cur showed a promising of DPPH free radicals scavenging capacity. • Cytotoxicity tests showed that ACCP and ACCP-Cur have low and high cells toxicity, respectively. [ABSTRACT FROM AUTHOR]