Gang Guo

Improving the anti-ovarian cancer activity of docetaxel with biodegradable self-assembly micelles through various evaluations

Docetaxel (DOC) produces anti-tumor effects by inducing apoptosis and inhibiting cell growth. However, its clinical application is limited by its hydrophobicity and low biocompatibility. Therefore, improving DOCs water solubility, biocompatibility, and anti-tumor effects are important goals that will improve its clinical utility. In this work, DOC and methoxy poly(ethylene glycol) (MPEG)/polycaprolactone (PCL) (MPEG-PCL) showed good compatibility through computer simulations. We prepared DOC-loaded polymeric micelles (DOC/MPEG-PCL micelles) with drug loading of 6.82% and encapsulation efficiency of 98.36%; these were monodispersed and approximately 30xa0nm in diameter, and released DOC over an extended period inxa0vitro and inxa0vivo. In addition, DOC/MPEG-PCL micelles inhibited cell growth and induced apoptosis more effectively than free DOC inxa0vitro. Furthermore, DOC/MPEG-PCL micelles inhibited ovarian tumor growth more significantly than free DOC. Immunohistochemical analysis indicated that DOC/MPEG-PCL micelles improved DOCs anti-tumor effect by enhancing tumor cell apoptosis and suppressing tumor cell proliferation. Moreover, in bio-imaging analysis, DOC/MPEG-PCL micelles showed a higher concentration and a longer retention time in ovarian tumor tissue than did free DOC, indicating that the DOC/MPEG-PCL micelles delivered more anti-tumor drug to the tumor. Our data suggest that DOC/MPEG-PCL micelles have the potential to be applied clinically in ovarian cancer therapy.

Increased expression of S100A6 promotes cell proliferation and migration in human hepatocellular carcinoma

High levels of S100A6 have been associated with poor outcome in some types of human cancers, but the role of S100A6 in the molecular pathogenesis of these cancers is largely unknown. This study was performed to explore the expression and functional roles of S100A6 in hepatocellular carcinoma (HCC). The expression level of S100A6 in HCC tumor and corresponding peritumoral tissues were determined by immunohistochemistry analysis. The potential functions of S100A6 in tumorigenesis and metastasis were analyzed by cell proliferation, migration, and invasion assays in human liver cancer cells. Moreover, through expression and purification of S100A6 recombinant protein tagged with cell-penetrating peptide, we analyzed its complex extracellular/intracellular effects in a S100A6-silenced cellular model. As a result, the expression of S100A6 was up-regulated in human HCC compared with adjacent peritumoral tissues. S100A6 silencing inhibited the growth and motility of HCC cells, while intracellular re-expression of S100A6 could rescue the proliferation and migration defects. Intracellular over-expression of S100A6 resulted in down-regulation of E-cadherin expression and promoted nuclear accumulation of β-catenin. Moreover, we found that the enhanced cell proliferation and motility after S100A6 stimulation were dependent on the activation of PI3K/AKT pathway. These results suggest that S100A6 may be involved in promotion and progression of human liver cancer.Key MessagesS100A6 is overexpressed in human hepatocellular carcinoma clinical specimens.S100A6 promotes proliferation and migration of human hepatoma cells.Overexpression of S100A6 results in alteration of E-cadherin and β-catenin.The multi-effects of S100A6 may be mediated in part by PI3K/AKT pathway activation.

In situ gel-forming AP-57 peptide delivery system for cutaneous wound healing.

In situ gel-forming system as local drug delivery system in dermal traumas has generated a great interest. Accumulating evidence shows that antimicrobial peptides play pivotal roles in the process of wound healing. Here in this study, to explore the potential application of antimicrobial peptide in wound healing, biodegradable poly(L-lactic acid)-Pluronic L35-poly(L-lactic acid) (PLLA-L35-PLLA) was developed at first. Then based on this polymer, an injectable in situ gel-forming system composed of human antimicrobial peptides 57 (AP-57) loaded nanoparticles and thermosensitive hydrogel was prepared and applied for cutaneous wound healing. AP-57 peptides were enclosed with biocompatible nanoparticles (AP-57-NPs) with high drug loading and encapsulation efficiency. AP-57-NPs were further encapsulated in a thermosensitive hydrogel (AP-57-NPs-H) to facilitate its application in cutaneous wound repair. As a result, AP-57-NPs-H released AP-57 in an extended period and exhibited quite low cytotoxicity and high anti-oxidant activity in vitro. Moreover, AP-57-NPs-H was free-flowing liquid at room temperature, and can form non-flowing gel without any crosslink agent upon applied on the wounds. In vivo wound healing assay using full-thickness dermal defect model of SD rats indicated that AP-57-NPs-H could significantly promote wound healing. At day 14 after operation, AP-57-NPs-H treated group showed nearly complete wound closure of 96.78 ± 3.12%, whereas NS, NPs-H and AP-57-NPs group recovered by about 68.78 ± 4.93%, 81.96 ± 3.26% and 87.80 ± 4.62%, respectively. Histopathological examination suggested that AP-57-NPs-H could promote cutaneous wound healing through enhancing granulation tissue formation, increasing collagen deposition and promoting angiogenesis in the wound tissue. Therefore, AP-57-NPs-H might have potential application in wound healing.

Facile Construction of Chloroquine Containing PLGA-Based pDNA Delivery System for Efficient Tumor and Pancreatitis Targeting in Vitro and in Vivo

Chloroquine diphosphate (CQ) was ingeniously used to take place of phosphate salt in traditional calcium phosphate coprecipitation method for pDNA transfection. With multiple roles of CQ in the novel Ca-CQ-pDNA complex including pDNA compaction and assistance in lysosome escape, the transfection efficiency of the pDNA was significantly increased relative to the traditional method. CQ did not intercalate into the DNA double helix as free CQ did, which was probably ascribed to the prior mixing of the pDNA with high concentration of calcium chloride. In order to construct efficacious vector for in vivo gene delivery, Ca-CQ-pDNA-PLGA-NPs was designed and prepared. With entrapment efficiency, particle size and pDNA integrity as screening conditions, the optimal prescription was obtained and CaPi-pDNA-PLGA-NPs made with classic calcium phosphate coprecipitation method after optimization was also prepared as control to systematically study the role of CQ in the novel vector. Physical characters of the vectors were comprehensively studied using TEM, DSC, and XRD. The safety of the vector both in vitro and in vivo was evaluated using MTT, hemolysis test, and histological sections. The Ca-CQ-pDNA-PLGA-NPs dramatically enhanced the gene tranfection efficiency in Human Embryonic kidney HEK293 cells compared with the CaPi-pDNA-PLGA-NPs and presented an increasing gene transfection for up 144 h. The relative fast release of the CQ compared with pDNA from the nanoparticles was responsive for the increased transfection. The Did-labeled-Ca-CQ-pDNA-PLGA-NPs exhibited excellent tumor targeting efficiency and sustained circulation time in CT26 mouse model. The Ca-CQ-pDNA-PLGA-NP loaded with the plasmid pVITRO2 expressing mSurvivin-T34A protein gave 70% tumor inhibition rate, which was partially ascribed to CQ. The Ca-CQ-pDNA-PLGA-NPs showed high targeting efficiency in C57 acute pancreatitis model. In all, the Ca-CQ-pDNA-PLGA-NP was a promising candidate for targeted gene delivery to both tumor and pancreatitis.

Killing colon cancer cells through PCD pathways by a novel hyaluronic acid-modified shell-core nanoparticle loaded with RIP3 in combination with chloroquine

Due to extensive apoptosis defects and multidrug resistance, there is great interest regarding non-apoptotic programmed cell death (PCD) pathways, such as lysosomal-mediated programmed cell death (LM-PCD), necroptosis and autophagy. Because there is an intricate effector network among these PCD pathways, it is expected that they may act synergistically in cancer therapy. In this study, chloroquine (CQ) was found to significantly upregulate receptor-interacting protein kinase 3 (RIP3) expression, and RIP3 were involved in CQ-related autophagy. Overexpressed-eGFP-RIP3 co-localized with the selective autophagy receptor p62. mRIP3 overexpression in combination with CQ markedly increased the inhibition rate relative to that observed in the CQ-treatment group. Several experiments, including Hoechst staining, transmission electron microscopy (TEM) observation, the high-mobility group box 1 (HMGB1) release assay, Annexin V/PI staining and immunoblotting of proteins included in PCD pathways, verified that mRIP3 overexpression in combination with CQ induced lysosomal membrane permeabilization (LMP) and necroptosis of cancer cells, leading to cancer cell death. For tumor-targeted delivery, hyaluronic acid (HA)-modified, lipid-coated PLGA nanoparticles loaded with mRIP3-pDNA were prepared and characterized using a particle sizer, differential scanning calorimetry (DSC) and TEM. The nanoparticles exhibited ideal biocompatibility and good tumor-targeting efficiency, and the tumor inhibition rate of HA-Lip-PEI-mRIP3-PLGA-NPsxa0+xa0CQ was 80.2% in the CT26 mouse model. In this study, we attempted to treat tumors by inducing several alternative PCD pathways to shed light on the combination therapy of alternative PCD inducers.

LHD-Modified Mechanism-Based Liposome Coencapsulation of Mitoxantrone and Prednisolone Using Novel Lipid Bilayer Fusion for Tissue-Specific Colocalization and Synergistic Antitumor Effects.

Coencapsulation liposomes are of interest to researchers because they maximize the synergistic effect of loaded drugs. A combination regimen of mitoxantrone (MTO) and prednisolone (PLP) has been ideal for tumor therapy. MTO and PLP offer synergistic antitumor effects confirmed by several experiments in this research. The deduced synergistic mechanism is regulation of Akt signaling pathway including the targets of p-Akt, p-GSK-3β, p-s6 ribosomal protein, and p-AMPK by MTO reactivating PLP-induced apoptosis. The liposome fusion method is adopted to create coencapsulation liposomes (PLP-MTO-YM). Low molecular weight heparin-sodium deoxycholate conjugate (LHD) then is used as a targeting ligand to prove target binding and inhibition of angiogenesis. LHD-modified liposomes (PLP-MTO-HM) have a high entrapment efficiency around 95% for both MTO and PLP. DSC results indicate that both drugs interacted with liposomes to prevent drug leak during liposome fusion. DiD-C6-HM dyes colocalize well to tumor tissue, and coadministration of DiD-HM and C6-CM did not achieve dye colocalization until 24 h after administration. In both CT26 and B16F10 mouse model, PLP-MTO-HM shows a significantly higher tumor inhibition rate relative to the coadministration of MTO-HM and PLP-CM (p < 0.05 or p < 0.01). Thus, the coencapsulation system (PLP-MTO-HM) offers ideal antitumor effects relative to coadministration therapy due to enhanced synergistic effect, and this suggests a promising future for the tumor targeting vectors.

Fabrication and in vivo chondrification of a poly(propylene carbonate)/L-lactide-grafted tetracalcium phosphate electrospun scaffold for cartilage tissue engineering

Regenerative therapies that utilize stem cell differentiation in three-dimensional porous scaffolds have attracted significant interest in recent years. In this study, fibrous poly(propylene carbonate)/poly(L-lactic acid)-grafted tetracalcium phosphate (PPC/g-TTCP) scaffolds were prepared using an electrospinning method. The characteristics of the fabricated scaffolds were investigated using scanning electron microscopy, differential scanning calorimetry, thermogravimetric analyses, Fourier transform infrared spectroscopy, X-ray diffraction analyses, water contact angle measurements and tensile tests. Due to the importance of biocompatibility, rat bone marrow-derived stem cells were cultured on the scaffolds, and the cell proliferation was investigated using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assays. Subsequently, chondrogenic differentiation was induced in these cells in vitro and in vivo. Fourteen days later, chondrocyte-like cells had developed on the PPC/g-TTCP scaffolds, as evidenced by the accumulation of glycosaminoglycan and type II collagen. After subcutaneous transplantation into nude mice, a typical cartilage cell morphology was observed on the scaffolds. These findings suggest that PPC/g-TTCP scaffolds can support cartilage development and are excellent candidate scaffolds for cartilage defect repair.

Novel nanoscale topography on poly(propylene carbonate)/poly(ε-caprolactone) electrospun nanofibers modifies osteogenic capacity of ADCs

In this study, we electrospun novel poly(propylene carbonate)/poly(e-caprolactone) (PPC/PCL) nanofibers with a special nanoscale topography using a simple process. The characteristics of the fabricated scaffolds were investigated using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analyses (XRD), thermogravimetric analyses (TG), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), water contact angle measurements (WCA), tensile tests and Brunauer–Emmett–Teller (BET) surface area analysis. To determine whether the nanoscale topography altered mesenchyme stem cell adhesion proliferation and differentiation behavior, adipose tissue-derived stromal cells (ADCs) were cultured on pure PPC electrospun scaffolds with smooth nanotopography and PPC/PCL (20 wt% PCL) hybrid scaffold with nanoscale topography. The results reveal that PPC/PCL electrospun fibers with special inter-surface-connected pores possess a high BET surface area and could promote ADCs adhesion and proliferation. According to alizarin red S staining and von-Kossa staining assays, there are more calcium nodule deposits on scaffolds with inter-surface-connected pores.

AP-57/C10orf99 is a new type of mutifunctional antimicrobial peptide

Antimicrobial peptides (AMPs) are an evolutionarily conserved component of the innate immune response that provides host defence at skin and mucosal surfaces. Here, we report the identification and characterization of a new type human AMPs, termed AP-57 (Antimicrobial Peptide with 57 amino acid residues), which is also known as C10orf99 (chromosome 10 open reading frame 99). AP-57 is a short basic amphiphilic peptide with four cysteines and a net charge +14 (MW = 6.52, PI = 11.28). The highest expression of AP-57 were detected in the mucosa of stomach and colon through immunohistochemical assay. Epithelium of skin and esophagus show obvious positive staining and strong positive staining were also observed in some tumor and/or their adjacent tissues, such as esophagus cancer, hepatocellular carcinoma, squamous cell carcinoma and invasive ductal carcinoma. AP-57 exhibited broad-spectrum antimicrobial activities against Gram-positive Staphylococcus aureus, Actinomyce, and Fungi Aspergillus niger as well as mycoplasma and lentivirus. AP-57 also exhibited DNA binding capacity and specific cytotoxic effects against human B-cell lymphoma Raji. Compared with other human AMPs, AP-57 has its distinct characteristics, including longer sequence length, four cysteines, highly cationic character, cell-specific toxicity, DNA binding and tissue-specific expressing patterns. Together, AP-57 is a new type of multifunctional AMPs worthy further investigation.

Docetaxel load biodegradable porous microspheres for the treatment of colorectal peritoneal carcinomatosis.

Micro- and nanoparticle formulations are widely used to improve the bioavailability of low solubility drugs. In this study, biodegradable poly(L-lactide acid)-Pluronic L121-poly(L-lactide acid) (PLLA-L121-PLLA) was developed. And then a controlled drug delivery system (CDDS), docetaxel (DOC) loaded PLLA-L121-PLLA porous microsphere (DOC MS) was prepared for colorectal peritoneal carcinomatosis (CRPC) therapy. DOC MS was prepared by DOC and PLLA-L121-PLLA using an oil-in-water emulsion solvent evaporation method. The particle size, morphological characteristics, encapsulation efficiency, in vitro drug release studies and in vitro cytotoxicity of DOC MS have been investigated. In vitro release profile demonstrated a significant difference between rapid release of free DOC and much slower and sustained release of DOC MS. Furthermore, cytotoxicity assay indicated cytotoxicity was increased after DOC was encapsulated into polymeric microspheres. In addition, intraperitoneal administration of DOC MS could effectively suppress growth and metastasis of CT26 peritoneal carcinomatosis in vivo, and prolonged the survival of tumor bearing mice. Immunohistochemistry staining of tumor tissues with Ki-67 revealed that DOC MS induced a stronger anti-tumor effect by increasing apoptosis of tumor cells in contrast to other groups (P<0.05). Thus, our results suggested that DOC MS may have great potential applications in clinic.