A Combination of Chitosan, Cellulose, and Seaweed Polysaccharide Inhibits Postoperative Intra-abdominal Adhesion in Rats.

Intra-abdominal adhesion is a common complication after laparotomy. Conventional therapeutic strategies still cannot safely and effectively prevent this disorder. In this study, a combination of chitosan, cellulose, and seaweed polysaccharide (thereafter referred as CCS) was developed to significantly alleviate the formation of postoperative adhesion in rats with abdominal trauma. Transforming growth factor ß1 (TGF-ß1, an important promoter of fibrosis) and its downstream factors-namely, alpha-smooth muscle actin and plasminogen activator inhibitor-1 (PAI-1)-were effectively suppressed by CCS in vivo, and as a result, the activation of tissue plasminogen activator (tPA, may generate plasmin that is a fibrinolytic factor capable of breaking down fibrin) was significantly promoted, presenting antifibrosis effects of CCS. In addition, the activity of kinases [e.g., transforming growth factor-activated kinase 1 (TAK1), c-Jun N-terminal kinase (JNK)/Stress-activated Protein Kinase (SAPK), and p38] in the mitogen-activated protein kinase (MAPK) inflammation signaling pathway was also significantly suppressed by CCS in vivo, demonstrating anti-inflammatory functions of CCS. The histologic studies further confirmed the role of CCS in the inhibition of fibrosis, collagen deposition, inflammation, and vascular proliferation. These results indicate the clinical potential of CCS in the treatment of postoperative intra-abdominal adhesion. CCS may induce both antifibrosis and anti-inflammatory effects, potentially inhibiting the postoperative intra-abdominal adhesion. For antifibrosis effects, the expression of PAI-1 (a key factor for the adhesion formation) can be regulated by different TGF-ß1-associated signaling pathways, such as the Smads/p53 pathway, metalloproteinase/tissue inhibitor of matrix metalloproteinases pathway, Mitogen-activated Extracellular signal-regulated Kinase (MEK)/extracellular regulated protein kinase (ERK) pathway, and Yes-associated protein/transcriptional coactivator with PDZ-binding motif pathway. Following the downregulation of PAI-1 achieved by CCS, the activation of tPA (which may generate plasmin that is a fibrinolytic factor capable of breaking down fibrin) is significantly promoted. For anti-inflammation effects, CCS may suppress the phosphorylation of classic kinases (e.g., TAK1, JNK, and p38) in the MAPK signaling pathway. In addition to the MAPK pathway, inflammatory pathways, such as Nuclear Factor-κ-gene Binding(NF-κB), MEK/ERK, and Ras homologue protein/Rho associated coiled coil forming protein, are associated with the formation of intra-abdominal adhesion. Therefore, the prevention mechanisms of CCS will be further investigated in the future, with a hope of fully understanding of antiadhesion effects.

PtrHAT22, as a higher hierarchy regulator, coordinately regulates secondary cell wall component biosynthesis in Populus trichocarpa.

Homeodomain-leucine zipper (HD-Zip) II transcription factors (TFs) have been reported to play vital roles in diverse biological processes of plants. However, it remains unclear whether HD-Zip II TFs regulate secondary cell wall (SCW) in woody plants. In this study, we performed the functional characterization of a Populus trichocarpa HD-Zip II TF, PtrHAT22, which encodes a nuclear localized transcription repressor predominantly expressing in secondary developing tissues. Overexpression of PtrHAT22 showed arrested growths, including reduced heights and diameters above the ground, small leaves, and decreased biomass. Meanwhile, the contents of lignin, cellulose, and thickness of SCW significantly decreased, whilst the content of hemicellulose obviously increased in PtrHAT22 transgenic poplar. The expressions of some wood-associated TFs and structural genes significantly changed accordingly with the alternations of SCW characteristics in PtrHAT22 transgenic poplar. Furthermore, PtrHAT22 directly repressed the promoter activities of PtrMYB20, PtrMYB28, and PtrCOMT2, and bind two cis-acting elements that were specifically enriched in their promoter regions. Taken together, our results suggested that PtrHAT22, as a higher hierarchy TF like PtrWNDs, exerted coordination regulation of poplar SCW component biosynthesis through directly and indirectly regulating structural genes and different hierarchy TFs of SCW formation network.

In vitro and in vivo Evaluation of a Novel Estrogen-Targeted PEGylated Oxaliplatin Liposome for Gastric Cancer.

BACKGROUND: Chemotherapy is still the main first-line treatment for advanced metastatic gastric cancer, but it has the limitations of serious side effects and drug resistance. Conventional liposome has been substantially used as drug carriers, but they lack targeting character with lower drug bioavailability in tumor tissues. Based on the above problems, a novel estrogen-targeted PEGylated liposome loaded with oxaliplatin (ES-SSL-OXA) was prepared to further improve the metabolic behavior, the safety profile, and the anti-tumor efficacy of oxaliplatin. METHODS: Four kinds of oxaliplatin (OXA) liposomes were prepared by film hydration method. The obtained formulations were characterized in terms of entrapment efficiency (EE), particle size, and so on by HPLC and DLS (dynamic light scanning). The morphology of ES-SSL-OXA was detected by transmission electron microscope (TEM). The in vitro and in vivo targeting effect of ES-SSL-OXA was verified by fluorescence microscopy and in vivo imaging system in gastric cancer cells (SGC-7901) and tumor-bearing athymic mice. The in vitro and in vivo antitumor efficacies of ES-SSL-OXA were investigated on SGC-7901 cells and athymic tumor-bearing mice. Pharmacokinetic, biodistribution, and acute toxicity tests of ES-SSL-OXA were performed on ICR mice. RESULTS: The ES-SSL-OXA exhibited an average particle size of about 153.37 nm with an encapsulation efficiency of 46.20% and low leakage rates at 4°C and 25°C. In vivo and in vitro targeting study confirmed that ES-SSL-OXA could effectively target the tumor site. The antitumor activity demonstrated the strongest inhibition in tumor growth of ES-SSL-OXA. Pharmacokinetics and acute toxicity study showed that ES-SSL-OXA could significantly improve the metabolic behavior and toxicity profile of oxaliplatin. CONCLUSION: In this study, a novel estrogen-targeted long-acting liposomal formulation of OXA was successfully prepared. ES fragment effectively targeted the delivery system to tumor tissues which highly express estrogen receptor, providing a promising therapeutic method for gastric cancer in clinic.

Preparation, Characterization, and Pharmacokinetic Study of a Novel Long-Acting Targeted Paclitaxel Liposome with Antitumor Activity.

BACKGROUND: Breast cancer is the leading cause of cancer death in women. Chemotherapy to inhibit the proliferation of cancer cells is considered to be the most important therapeutic strategy. The development of long-circulating PEG and targeting liposomes is a major advance in drug delivery. However, the techniques used in liposome preparation mainly involve conventional liposomes, which have a short half-life, high concentrations in the liver and spleen reticuloendothelial system, and no active targeting. METHODS: Four kinds of paclitaxel liposomes were prepared and characterized by various analytical techniques. The long-term targeting effect of liposomes was verified by fluorescence detection methods in vivo and in vitro. Pharmacokinetic and acute toxicity tests were conducted in ICR mice to evaluate the safety of different paclitaxel preparations. The antitumor activity of ES-SSL-PTX was investigated in detail using in vitro and in vivo human breast cancer MCF-7 cell models. RESULTS: ER-targeting liposomes had a particle size of 137.93±1.22 nm and an acceptable encapsulation efficiency of 88.07±1.25%. The liposome preparation is best stored at 4°C, and is stable for up to 48 hrs. Cytotoxicity test on MCF-7 cells demonstrated the stronger cytotoxic activity of liposomes in comparison to free paclitaxel. We used the near-infrared fluorescence imaging technique to confirm that ES-SSL-PTX was effectively targeted and could quickly and specifically identify the tumor site. Pharmacokinetics and acute toxicity in vivo experiments were carried out. The results showed that ES-SSL-PTX could significantly prolong the half-life of the drug, increase its circulation time in vivo, improve its bioavailability and reduce its toxicity and side effects. ES-SSL-PTX can significantly improve the pharmacokinetic properties of paclitaxel, avoid allergic reaction of the original solvent, increase antitumor efficacy and reduce drug toxicity and side effects. CONCLUSION: ES-SSL-PTX has great potential for improving the treatment of breast cancer, thereby improving patient prognosis and quality of life.

Co-delivery of epirubicin and paclitaxel using an estrone-targeted PEGylated liposomal nanoparticle for breast cancer.

Breast cancer is one of the most frequent malignancies in the female population. Recently, the development of medical products has been advanced for this disease; however, patients still suffer from the failure of current treatments and new therapeutic strategies are urgently required. In this study, due to the overexpression of the estrogen receptor (ER) in breast cancer and the ability of ER to specifically bind to its ligand estrone (ES), an ES-targeted PEGylated epirubicin (EPI) and paclitaxel (PTX) co-loaded liposomal nanoparticle (NP) (termed as ES-SSL-EPI/PTX) was developed. Physicochemical studies demonstrated that the ES-SSL-EPI/PTX had a nanoscaled particle size (~120 nm) and a neutral zeta potential (~-5 mV) and presented favorable stability in physiological media. In vitro, the ES-SSL-EPI/PTX showed a significantly higher cellular uptake in human breast cancer MCF-7 cells mainly via the receptor-ligand mediated pathway resulting in effective cytotoxic activity. In vivo targeting study, the accumulation of targeted liposomes in tumor was significantly improved. The systemic circulation time and biodistribution in main organs of EPI and PTX delivered by ES-SSL-Liposomes were increased. Consequently, the ES-SSL-EPI/PTX significantly suppressed tumor growth in the MCF-7-derived tumor-bearing mouse model without inducing toxicity. These results suggested that the ES-SSL-EPI/PTX was a promising formulation for co-delivery of chemotherapeutics in the treatment of breast cancer.

Anisamide-targeted PEGylated gold nanoparticles designed to target prostate cancer mediate: Enhanced systemic exposure of siRNA, tumour growth suppression and a synergistic therapeutic response in combination with paclitaxel in mice.

Small interfering RNA (siRNA) has recently illustrated therapeutic potential for malignant disorders. However, the clinical application of siRNA-based therapeutics is significantly retarded by the paucity of successful delivery systems. Recently, multifunctional gold nanoparticles (AuNPs) as non-viral delivery carriers have shown promise for transporting chemotherapeutics, proteins/peptides, and genes. In this study, AuNPs capped with polyethylenimine (PEI) and PEGylated anisamide (a ligand known to target the sigma receptor) have been developed to produce a range of positively charged anisamide-targeted PEGylated AuNPs (namely Au-PEI-PEG-AA). The anisamide-targeted AuNPs effectively complexed siRNA via electrostatic interaction, and the resultant complex (Au110-PEI-PEG5000-AA.siRNA) illustrated favourable physicochemical characteristics, including particle size, surface charge, and stability. In vitro, anisamide-targeted AuNPs selectively bound to human prostate cancer PC-3 cells, inducing efficient endosomal escape of siRNA, and effective downregulation of the RelA gene. In vivo, prolonged systemic exposure of siRNA was achieved by anisamide-targeted AuNPs resulting in significant tumour growth suppression in a PC3 xenograft mouse model without an increase in toxicity. In addition, a combination of siRNA-mediated NF-κB knockdown using anisamide-targeted AuNPs with Paclitaxel produced a synergistic therapeutic response, thus providing a promising therapeutic strategy for the treatment of prostate cancer.

Oestrone-targeted liposomes for mitoxantrone delivery via oestrogen receptor - synthesis, physicochemical characterization and in-vitro evaluation.

OBJECTIVES: Targeted delivery of mitoxantrone (MTO, an anthraquinone drug with high antitumour effect) may be achieved using a novel nanoparticulate delivery system via binding the oestrogen receptor (ER, highly expressed in a variety of human tumours). METHODS: A novel liposomal nanoparticle (NP) was developed using a conjugate derived from 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino (polyethylene glycol)-2000] (DSPE-PEG2000 -NH2 ) and oestrone (ES, is known to bind the ER) to produce an ES-targeted PEGylated liposome (ES-SSL). The resulting targeted NP was loaded with MTO to produce a targeted liposome-MTO formulation (ES-SSL-MTO). KEY FINDINGS: The targeted formulation (~140 nm, 1.5 mV) achieved over 95% drug encapsulation efficiency and a favourable stability at 4, 25 and 37 °C up to 48 h. The flow cytometric data indicated that cellular uptake of ES-SSL into human leukaemia HL-60 cells was mediated via binding the oestrogen receptor. In addition, the ES-SSL-MTO significantly reduced the growth of HL-60 cells. CONCLUSIONS: Our results provide a proof of principle that ES-modified PEGylated liposomes can target the ER, thereby potentially improving the therapeutic benefits in ER-overexpressed tumours.