GCN5 regulates ZBTB16 through acetylation, mediates osteogenic differentiation, and affects orthodontic tooth movement.

In the process of orthodontic tooth movement (OTM), periodontal ligament fibroblasts (PDLFs) must undergo osteogenic differentiation. OTM increased the expression of Zinc finger and BTB domain-containing 16 (ZBTB16), which is implicated in osteogenic differentiation. Our goal was to investigate the mechanism of PDLF osteogenic differentiation mediated by ZBTB16. The OTM rat model was established, and PDLFs were isolated and exposed to mechanical force. Hematoxylin-eosin staining, Alizarin Red staining, immunofluorescence, and immunohistochemistry were carried out. The alkaline phosphatase (ALP) activity was measured. Dual-luciferase reporter gene assay and chromatin immunoprecipitation assay were conducted. In OTM models, ZBTB16 was significantly expressed. Additionally, there was an uneven distribution of PDLFs in the OTM group, as well as an increase in fibroblasts and inflammatory infiltration. ZBTB16 interference hindered PDLF osteogenic differentiation and decreased Wnt and ß-catenin levels. Meanwhile, ZBTB16 activated the Wnt/ß-catenin pathway. ZBTB16 also enhanced the expression of the osteogenic molecules osterix, osteocalcin (OCN), osteopontin (OPN), and bone sialo protein (BSP) at mRNA and protein levels. The interactions between Wnt1 and ZBTB16, as well as GCN5 and ZBTB16, were also verified. The adeno-associated virus-shZBTB16 injection also proved to inhibit osteogenic differentiation and reduce tooth movement distance in in vivo tests. ZBTB16 was up-regulated in OTM. Through acetylation modification of ZBTB16, GCN5 regulated the Wnt/ß-catenin signaling pathway and further mediated PDLF osteogenic differentiation.

Construction a Long-Circulating Delivery System of Liposomal Curcumin by Coating Albumin.

Although the bioavailability and stability of curcumin can be greatly improved by liposomes encapsulation, its application is still limited due to the short circulating time. In this present work, we aim to construct a long-circulating delivery system of liposomal curcumin (Cur-Lips) by coating bovine serum albumin (BSA), namely, BSA-coated liposomal curcumin (BSA-Cur-Lips). The effects of coating albumin on the physicochemical properties of Cur-Lips were investigated. It was found that BSA-Cur-Lips was more spherical, more homogeneous in size, and significantly larger than Cur-Lips. Combining sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Coomassie bright blue staining, and X-ray photoelectron spectroscopy analysis (XPS), we confirmed that albumin molecules were stably located on the surface of BSA-Cur-Lips. In addition, the impacts of the coating albumin on the Cur-Lips release and phagocytosis by mouse macrophages Raw264.7 in vitro were investigated. We found that no significant initial burst drug release effect was observed for both Cur-Lips and BSA-Cur-Lips and the presence of albumin can enhance the liposome structure stability and slow down the release of Cur. More importantly, the macrophage phagocytosis of Cur-Lips was significantly reduced after coating albumin. In conclusion, coating albumin is a promising approach for developing a long-circulating delivery system of liposomal curcumin, and its properties including low phagocytosis, slow drug release, enhanced stability, and nontoxicity give this system great prospects for practical use.

[Chondrocyte cocultures with stromal vascular fraction of adipose tissue promote cartilage regeneration in vivo].

OBJECTIVE: This study aimed to compare the cartilage regeneration of the stromal vascular fraction (SVF) cells and adipose-derived mesenchymal stem cells (ASCs) cocultured with chondrocytes seeded on the scaffolds. METHODS: The cellular morphologies and proliferation capabilities on the scaffolds were evaluated. The scaffolds with the cocul-ture of ASCs/SVF and chondrocytes were implanted into the full thickness cartilage defective rabbit joints for 10 weeks. RESULTS: The cells seeded into the scaffolds showed good adhesion and proliferation. Implantation with SVF and chondrocytes revealed desirable in vitro healing outcomes. CONCLUSIONS: The SVF cells were better than ASCs in terms of the formation of cartilage matrix in a coimplantation model. Without in vitro expansion, the SVF cells are good cell sources for cartilage repair.

Improving the Stability of Liposomal Curcumin by Adjusting the Inner Aqueous Chamber pH of Liposomes.

Curcumin (CURC) is a hydrophobic molecule and its water solubility can be greatly improved by liposome encapsulation. However, investigations on the stability of pH-sensitive molecules incorporated into liposomal membranes are limited. In this study, CURC-loaded liposomes with varied internal pH values (pH 2.5, 5.0, or 7.4) were prepared and designated as CURC-LP (pH 2.5), CURC-LP (pH 5.0), and CURC-LP (pH 7.4). Physical properties including particle size, ζ-potential, morphology, entrapment efficiency, and physical stabilities of these CURC-LPs were assessed. In addition, the chemical stability of liposomal CURC to different external physiological environments and internal microenvironmental pH levels were investigated. We found that among these CURC-LPs, CURU-LP (pH 2.5) has the highest entrapment efficiency (73.7%), the best physical stabilities, and the slowest release rate in vitro. Liposomal CURC remains more stable in an acid external environment. In the physiological environment, the chemical stability of liposomal CURC is microenvironmental pH-dependent. In conclusion, we prove that the stability of liposomal CURC is external physiological environment- and internal microenvironmental pH-dependent. These findings suggest that creating an acidic microenvironment in the internal chamber of liposomes is beneficial to the stability of liposomal CURC, as well as for other pH-sensitive molecules.

Cosmetic and Skincare Benefits of Cultivated Mycelia from the Chinese Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes).

Mushrooms are potential sources of novel natural cosmeceutical ingredients. This study was conducted to evaluate the cosmetic (skincare) benefits of the valuable medicinal species Ophiocordyceps sinensis (=Cordyceps sinensis). The mycelial extracts of 2 O. sinensis strains, Cs-HK1 and Cs-4, prepared sequentially with ethyl acetate, ethanol, and hot water were tested with in vitro assays for tyrosinase-, collagenase-, and elastase-inhibitory activity. The ethyl acetate extracts of both fungal strains showed potent antityrosinase and antielastase activity, with low half-maximal inhibitory concentrations (0.14-0.47 mg/mL) comparable to those of the respective reference compounds (arbutin and epigallocatechin gallate). All mycelial extracts exhibited moderate or significant anticollagenase activity; most extracts showed a significant photoprotective effect with a sun protection factor up to 25. The results from this study show the potential use of O. sinensis as a source of cosmetic ingredients for skincare applications.

Effects of Micro-environmental pH of Liposome on Chemical Stability of Loaded Drug.

Liposome is a promising carrier system for delivering bioactive molecules. However, the successful delivery of pH-sensitive molecules is still limited by the intrinsic instability of payloads in physiological environment. Herein, we developed a special liposome system that possesses an acidic micro-environment in the internal aqueous chamber to improve the chemical stability of pH-sensitive payloads. Curcumin-loaded liposomes (Cur-LPs) with varied internal pH values (pH 2.5, 5.0, or 7.4) were prepared. These Cur-LPs have similar particle size of 300 nm, comparable physical stabilities and analogous in vitro release profiles. Interestingly, the chemical stability of liposomal curcumin in 50% fetal bovine serum and its anticancer efficacy in vitro are both micro-environmental pH-dependent (Cur-LP-2.5 > Cur-LP-5.0 > Cur-LP-7.4). This serum stability still has space to be further enhanced to improve the applicability of Cur-LP. In conclusion, creating an acidic micro-environment in the internal chamber of liposome is feasible and efficient to improve the chemical stability of pH-sensitive payloads.

Understanding the Biomedical Effects of the Self-Assembled Tetrahedral DNA Nanostructure on Living Cells.

Recently, much attention has been paid to DNA again due to the successful synthesis of DNA-based nanostructures that can enter cells via endocytosis and thus have great potential in biomedical fields. However, the impacts of DNA nanostructures on life activities of a living cell are unknown. Herein, the promotion effect of tetrahedral DNA nanostructure (TDN) on cell growth and the underlying molecular mechanisms are reported. Upon exposure to TDN, cell proliferation is significantly enhanced, accompanied by up-regulation of cyclin-dependent kinase like-1 gene, changes in cell cycle distribution, and up-regulation of the Wnt/ß-catenin signaling-related proteins (ß-catenin, Lef 1 and cyclin D). In contrast, single-stranded DNA (ssDNA) shows no such functions. Furthermore, TDN is able to reverse the inhibition effect of DKK1, a specific inhibitor for Wnt/ß-catenin pathway. Hence, the Wnt/ß-catenin pathway is the target for TDN to promote cell proliferation. The findings allow TDN to be a novel functional nanomaterial that has great potential in tissue repair and regeneration medicine.

Insight into the Interaction of Graphene Oxide with Serum Proteins and the Impact of the Degree of Reduction and Concentration.

As novel applied nanomaterials, both graphene oxide (GO) and its reduced form (rGO) have attracted global attention, because of their excellent properties. However, the lack of comprehensive understanding of their interactions with biomacromolecules highly limits their biomedical applications. This work aims to initiate a systematic study on the property changes of GO/rGO upon interaction with serum proteins and on how their degree of reduction and exposure concentration affect this interaction, as well as to analyze the possible biomedical impacts of the interaction. We found that the adsorption of proteins on GO/rGO occurred spontaneously and rapidly, leading to significant changes in size, zeta potential, and morphology. Compared to rGO, GO showed a higher ability in quenching intrinsic fluorescence of serum proteins in a concentration-dependent manner. The protein adsorption efficiency and the types of associated proteins varied, depending on the degree of reduction and concentration of graphene. Our findings indicate the importance of evaluating the potential protein adsorption before making use of GO/rGO in drug delivery, because the changed physicochemical properties after protein adsorption will have significant impacts on safety and effectiveness of these delivery systems. On the other hand, this interaction can also be used for the separation, purification, or delivery of certain proteins.

Independent effect of polymeric nanoparticle zeta potential/surface charge, on their cytotoxicity and affinity to cells.

OBJECTIVES: Up to now, little research has been focussed on discovering how zeta potential independently affects polymeric nanoparticle (NP) cytotoxicity. METHODS: Polymeric nanoparticles of gradient zeta potential ranging from -30 mv to +40 mv were fabricated using the same poly-3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBHHx) biopolymer. Interaction forces between nanoparticles and cells were measured by atomic force microscopy (AFM). Cytotoxicity of the nanoparticles to cells was investigated by using MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay. RESULTS: Four kinds of nanoparticle with similar sizes and gradient zeta potentials, were fabricated. Those with positive surface charges were found to be more toxic than those with negative surface charges. Positively charged nanoparticles or nanoparticles with higher 'like' charges, offered higher interaction force with cells. CONCLUSION: This work proposes a novel approach for investigating interaction between NPs and cells, and discloses the importance of controlling zeta potential in developing NPs-based formulations in the future.

Enhanced biostability of nanoparticle-based drug delivery systems by albumin corona.

AIMS: The long-term efficacy of nanoparticles is limited by their rapid metabolism in tissues. In this work, we aim to enhance nanoparticle biostability by preforming a bovine serum albumin (BSA) corona. MATERIALS & METHODS: A BSA corona was formed by incubating poly-3-hydroxybutyrate-co-3-hydroxyhexanoate nanoparticles with BSA solution and confirmed by SDS-PAGE and x-ray photoelectron spectroscopy. The impacts of the BSA corona on the drug release, biostability and biodistribution of nanoparticles were investigated. RESULTS: In the presence of the BSA corona, the drug release (coumarin-6 was used as the model drug) of nanoparticles was significantly slower and their stability in liver homogenate and in organs was enhanced. CONCLUSION: Preformation of a BSA corona may be a promising approach for enhancing drug biostability and for developing long-acting nanoparticle formulations.

Nanocomplex based on biocompatible phospholipids and albumin for long-circulation applications.

Achieving long circulating delivery of nanoparticles (NPs) is important for efficient drug therapy, but it is difficult due largely to proteins adsorption (opsonization) or/and nonsufficient stability of NPs. In this present work, we aimed to address the above issues by constructing a phospholipid and BSA-based nanocomplex system, namely BSA-phospholipid NPs (BSA-PL-NPs). Combining sodium dodecyl sulfate-polyacrylamide gel electrophoresis, X-ray photoelectron spectroscopy and proteins adsorption property, we confirmed that some BSA molecules were fixed on the inner surface of BSA-PL-NPs via hydrophobic interactions and the others were located in the core area. This special configuration allowed BSA-PL-NPs to not only maintain the antiadsorption and low phagocytosis properties but also have the slow zero-order drug release and the enhanced nanostructure stability. Interestingly, we found that BSA-PL-NPs had no cytotoxicity to mouse L929 fibroblasts but could stimulate the cells' growth instead. In conclusion, BSA-PL-NPs have a great potential to be developed as a long-circulation drug delivery system, and the ready availability, biocompatibility and nontoxicity of phospholipids and albumin give this system great promise for practical use.

Preformed albumin corona, a protective coating for nanoparticles based drug delivery system.

The non-specific interaction between nanoparticles (NPs) and plasma proteins occurs immediately after NPs enter the blood, resulting in the formation of the protein corona that thereafter replaces the original NPs and becomes what the organs and cells really see. Consequently, the in vivo fate of NPs and the biological responses to the NPs are changed. This is one substantial reason for the two main problems of the NPs based drug delivery system, i.e. nanotoxicity and rapid clearance of NPs from the blood after intravenous injection. Here, we demonstrate the successful application of the preformed albumin corona in inhibiting the plasma proteins adsorption and decreasing the complement activation, and ultimately in prolonging the blood circulation time and reducing the toxicity of the polymeric PHBHHx NPs. Since the interaction of proteins with various nano-materials and/or -particles is ubiquitous, pre-forming albumin corona has a great potential to be a versatile strategy for optimizing the NPs based drug delivery system.