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Background Combined chemotherapy is often affected by the different physicochemical properties of chemotherapeutic drugs, which should be improved by the reasonable design of co-loaded preparations. Purpose A kind of simple but practical graphene oxide (GO) wrapped mesoporous silica nanoparticles (MSN) modified with hyaluronic acid (MSN@GO-HA) were developed for the co-delivery of cinnamaldehyde (CA) and doxorubicin (DOX), in order to enhance their combined treatment on tumor cells and reduce their application defects. Methods The MSNCA@GODOX-HA was constructed by MSNCA (loading CA via physical diffusion) and GODOX-HA (modified with HA and loading DOX via π–π stacking) through the electrostatic adsorption, followed by the physicochemical characterization, serum stability and in vitro release study. Cytotoxicity on different cells was detected, followed by the tumor cell uptake tests. The intracellular reactive oxygen species (ROS) changes, mitochondrial functions and activities of caspase-3/-9 in MCF-7 cells were also evaluated, respectively. Results The MSNCA@GODOX-HA nanoparticles kept stable in FBS solution and achieved pH-responsive release behavior, which was beneficial to increase the accumulation of CA and DOX in tumor cells to enhance the treatment. MSNCA@GODOX-HA exerted higher cytotoxicity to MCF-7 human breast cancer cells than H9c2 cardiac myocyte cells, which were not only attributed to the active targeting to tumor cells by HA, but also related with the activation of intrinsic apoptotic pathway in MCF-7 cells induced by CA, which was mediated by the specific ROS signal amplification and the interference with mitochondrial function. Moreover, the efficacy of DOX was also enhanced by the above process. Conclusion The establishment of the MSNCA@GODOX-HA nanoparticles played a role in promoting strengths and restricting shortcomings of CA and DOX, thereby exerting their function and achieving efficient treatment against cancer.

In this article, the layered deposition method is adopted to prepare the collagen/hydroxyapatite (COL/HA) composite coating. The morphology and elements of the COL/HA composite coating are observed using a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), the optical density (O.D.) values are obtained by MTT assay to assess the cellular viabilityof composite coating. The experimental results showed that the addition of collagen not only improve the bonding strength of composite coating and porous titanium substrate, but also combine the osteoconduction of inorganic coating HA and the osteoinduction of organic coating COL, effectively enhance the cellular adhesion, proliferation and differentiation. The cellular viability cultured in COL/HA composite coating is much higher than the pure HA modified coating.

In this article, osteoblast activity on two functionalised hydroxyapatite (HA) and hydroxyapatite/collagen (HA+COL) surface layers is studied, and the effects of the concentrations of collagen and the collagen adding method on osteoblast activity are investigated. The morphology and elements of the HA and HA+COL on porous titanium are observed using a scanning electron microscope and an energy dispersive spectrometer. The number of living osteoblasts is found by comparing the optical density value against a control group. The experimental results showed that osteoblasts have different responses at HA and HA+COL surfaces that have different chemical compositions. The different concentrations and the means of collagen addition can all significantly improve the survival rate of the osteoblasts, but a 7 mg mL−1 concentration of the added amount of collagen in cell activity gives the best result. It can be concluded that collagen molecules deposit on the HA-coating uniformly and provide a favourable position f...

A hydroxyapatite coating on the porous titanium surface was prepared by NaOH-treated and heat treatment followed by immersing into a supersaturated calcium phosphate solution. It is found that the porous titanium was in an open-cell microstructure. The morphology, element content and phase composition of the hydroxyapatite coating were also analyzed. The cytotoxicity of porous titanium surface were tested. The results showed the hydroxyapatite of porous titanium surface by NaOH-treated and heat treatment was attached uniformly and had a certain thickness after immersion into the simulated body fluid (SBF) solution for 5 days, the hydroxyapatite coating was formed after immersion into the SBF solution for 12 days, it demonstrated good biocompatibility and enhancement of biological activity, it was conducive to the proliferation and adhesion of osteoblasts.

Three methods have been used to modify the porous titanium surface, which is the alkali heat treatment, alkali heat treatment + SBF solution soak and alkali heat treatment + precalcidied + SBF solution soak. The morphology of different surfaces was observed by scanning electron microscopy (SEM). The MC3T3-E1 osteoblast cell was cultured on the modified and unmodified surface of porous titanium with 3days and 7days, the morphology of osteoblast adhesion and growth on different surface was observed. The results showed that osteoblast adhere on the modified and unmodified surface of the porous titanium. Osteoblast on AHS and HA modified surface can grow and spread, but it cannot grow and spread on unmodified and AH modified surface of the porous titanium. Osteoblast can grow across the different titanium fibers of on HA modified surface of porous titanium. Osteoblast on the HA surface has the very good biological suitability, which is beneficial to the combination of bone tissue and porous titanium.

The adsorption kinetics is studied for 1-decanol by using pendant bubble tensiometry enhanced by video digitization. Cohesive forces between decanol molecules adsorbed onto an air-water interface play an important role in the sorption kinetics. Intermolecular cohesive forces among the adsorbed molecules raise the energy barrier for desorption of the adsorbed molecules into the bulk sublayer and correspondingly lower the desorption rate. For adsorption onto an initially clean interface, a reduction in the desorption rate affects the tail end of the process and diffusion is the rate-controlled step. After the establishment of equilibrium, adsorbed monolayers at the air-water interface are compressed by shrinking the air bubble slightly. The subsequent re-equilibration, affected by the lower desorption rate during the entire period of the process, is controlled by both diffusion and sorption kinetics. A diffusion coefficient is computed by comparing the dynamic surface tension profiles of clean adsorption with numerical solutions of bulk surfactant diffusion equation and a generalized Frumkin adsorption isotherm. The adsorption and desorption rate constants are determined from the experimental relaxation of re-equilibration.

Poly (2-ethylacrylic acid) (PEAA) alkylamide derivatives were synthesized for constructing pH-sensitive liposomes by partially modification of carboxylic groups of PEAA with chemical reaction. These lipid derivatives of PEAA were synthesized by partially modification of carboxylic groups of PEAA with alkylamines. The acid-sensitive polymer associated liposomes were obtained by the method of polymer self-insertion in aqueous solutions through inserting hydrophobic lipid anchors of the polymer PEAA derivatives into the outer layer of vesicles. Factor effects on polymer insertion into liposomes were evaluated and the pH-sensitivity of the polymer associated liposomes was studied by calcein release assay. The PEAA-assoeiated-liposomes were prepared successfully by the methods of self-insertion. The PEAA-associated-liposomes are shown to be stable at neutral pH. (1) There was no correlate of anchor density of PEAA with length of the alkyl chain, but was positively correlated with the degree of PEAA modification. (2) Polymer insertion increased with initial ratio of polymer to lipid. (3) Unerting hydrophobic lipidr acidic conditions the associated polymer induces membrane disruption and fusion. (4) The PEAA-associated-liposomes shown pH-sensitive drug release property under acidic conditions. The anchored-poly (ethylacrylic acid) lipid derivatives can be useful in developing a potential pH sensitive drug delivery system.