Preparation of endostatin-loaded chitosan nanoparticles and evaluation of the antitumor effect of such nanoparticles on the Lewis lung cancer model.

The purpose of this study was to prepare ES-loaded chitosan nanoparticles (ES-NPs) and evaluate the antitumor effect of these particles on the Lewis lung cancer model. ES-NPs were prepared by a simple ionic cross-linking method. The characterization of the ES-NPs, including size distribution, zeta potential, loading efficiency and encapsulation efficiency (EE), was performed. An in vitro release test was also used to determine the release behavior of the ES-NPs. Cell viability and cell migration were assayed to detect the in vitro antiangiogenic effect of ES-NPs. In order to clarify the antitumor effect of ES-NPs in vivo, the Lewis lung cancer model was used. ES-NPs were successfully synthesized and shown to have a suitable size distribution and high EE. The nanoparticles were spherical and homogeneous in shape and exhibited an ideal releasing profile in vitro. Moreover, ES-NPs significantly inhibited the proliferation and migration of human umbilical vascular endothelial cells (HUVECs). The in vivo antiangiogenic activity was evaluated by ELISA and immunohistochemistry analyses, which revealed that ES-NPs had a stronger antiangiogenic effect for reinforced anticancer activity. Indeed, even the treatment cycle in which ES-NPs were injected every seven days, showed stronger antitumor effect than the free ES injected for 14 consecutive days. Our study confirmed that the CS nanoparticle is a feasible carrier for endostatin to be used in the treatment of lung cancer.

ANGIOGENESIS INHIBITOR ENDOSTATIN PROTECTS MICE WITH SEPSIS FROM MULTIPLE ORGAN DYSFUNCTION SYNDROME.

Endostatin is an endogenous inhibitor of vascular endothelium. It can inhibit endothelial cell migration, proliferation, and vascular angiogenesis and is mainly used for anticancer therapy. We have previously found that endostatin is an important node protein in the pathogenesis of sepsis. However, its impacts on sepsis have not yet been reported. We established a septic mouse model using cecal ligation and puncture (CLP) and gave the mice either endostatin or placebo (saline). The effects of endostatin on serum enzyme, Evans blue leakage, lung wet-to-dry weight ratio, and cytokine (tumor necrosis factor α, interleukin 1ß [IL-1ß], and IL-6) production were assessed. Survival rates were observed for up to 3 days. In addition, we examined the effects of endostatin on serum vascular endothelial growth factor A (VEGF-A), VEGF-C, and pathological changes and scores of lung tissues as well as the phosphorylation of JNK, p38, and ERKl/2 proteins in lung tissues of mice with sepsis. We found that endostatin can increase the survival of septic mice in a time- and dose-dependent manner probably by reducing multiorgan dysfunctions shown by serum indicators, morphologic changes, Evans blue leakage, wet-to-dry weight ratio, and inflammation of lung tissues. In addition, endostatin could reduce serum tumor necrosis factor α, IL-1ß, IL-6, and VEGF-C levels in septic mice as well as inhibit phosphorylation of p38 and ERK1/2 in lung tissues of septic mice. This is the first study demonstrating the protective effect of endostatin on sepsis and its possible underlying mechanisms from the aspects of inhibiting inflammatory responses, blocking VEGF receptor, attenuating VEGF-C expression, and reducing vascular permeability. Overall, the study revealed the potential protect role for endostatin in the treatment of sepsis.

Clinical Application of Recombinant Human Endostatin in Postoperative Early Complementary Therapy on Patients with Non-small Cell Lung Cancer in Chinese Mainland.

OBJECTIVE: To explore the clinical application of recombinant human endostatin (Endostar) in the treatment of patients with non-small cell lung cancer (NSCLC) in Chinese mainland. MATERIALS AND METHODS: A total of 75 patients diagnosed as NSCLC were randomly divided into control group (37 cases) and treatment group (38 cases). Control group was treated with postoperative complementary chemotherapy containing two-agent platinum protocol on postoperative d21, 3 weeks as a cycle, for totally 4~6 cycles. On this basis, treatment group was added with Endostar 7.5 mg/m2 on postoperative d8~9, 3~4 h/time, qd, 14 weeks as a cycle, for totally 4 cycles. The interval between every two cycles was 7 d. The 5-year progression-free survival (PFS), 5-year survival time and complications in both groups were observed. RESULTS: Compared with control group, the average PFS increased evidently in treatment group by 9.8 months (41.6 months vs. 31.8 months), and there was significant difference (P<0.05). And the median PFS was 42.5 months in treatment group, obviously longer than that in control group (33.7 months) by 8.8 months (P<0.05). Additionally, the 5-year overall survival rate (OS), average survival time and median survival time (MST) were 47.4%, 50.1 months and 59.3 months in treatment group, significantly higher than the 29.7%, 42.1 months and 43.5 months in control group (P<0.05). Only 1 patient showed poor healing of surgical wound in treatment group, but no surgery-associated complication was found in control group. Moreover, the postoperative complementary therapy-connected complication rates were 63.2% (24/38) and 59.5% (22/37) in treatment group and control group respectively, but there was no significant difference (P>0.05). CONCLUSIONS: The application of Endostar combined with sensitive platinum-contained chemotherapeutic agents in the postoperative complementary chemotherapy can be widely used in clinic because it can significantly prolong the long-term survival time of patients with NSCLC.

Bifidobacterium longum as an oral delivery system of endostatin for gene therapy on solid liver cancer.

To overcome difficulties that hampered widespread application of a specific delivery system in cancer gene therapy and to inhibit the growth of solid liver cancer, we utilized a strain of Bifidobacterium longum as a delivery system to transport an endostatin gene that can inhibit growth of tumor. The B. longum strain with the endostatin gene (B. longum-En) was taken orally by tumor-bearing nude mice through drencher preparation. The results showed that B. longum-En could strongly inhibit the growth of solid liver tumor in nude mice and prolong the survival time of tumor-bearing nude mice. Furthermore, tumor growth was inhibited more efficiently when the B. longum-En treatment included selenium. Enriching the B. longum-En treatment with selenium improves the activity of NK and T cells and stimulates the activity of IL-2 and TNF-alpha in BALB/c mice. These results suggest that B. longum may be a highly specific and efficient vector for transporting anticancer genes in cancer gene therapy.

Delivery of antiangiogenic and antioxidant drugs of ophthalmic interest through a nanoporous inorganic filter.

PURPOSE: We propose a novel method of administration of antiangiogenic and antioxidant drugs, with potential clinical application in the treatment of proliferative diabetic retinopathy (PDR) and age-related macular degeneration (AMD). We suggest the encapsulation of drugs in implantable sustained release devices, limited by membranes with pores in the tens of nanometers diameter range, which display a slower, quasi-linear release kinetics, and a better selectivity than other membranes. In this paper we explored the feasibility of this approach by testing in vitro several key elements of the nanofilter system: diffusion of drugs of interest, efficacy in producing desirable effects on cells, and biocompatibility of used material with some of the cells encountered in the ocular cavity. METHODS: We used an aluminum oxide filter (Anopore) with pores of 20 nm as a limiting medium for the administration of drugs. First, we induced an oxidative stress in human retinal endothelial cells (HREC) by treating them with hydrogen peroxide diffused across the filter, in the absence or in the presence of catalase. HREC attached to the culture plate, or emerging as angiogenic sprouts from aggregates embedded in collagen gels, were also exposed to vitamin C or to endostatin delivered across the nanoporous filter. Direct exposure of the cells to the agents served as positive controls. Growth of cells on the filter was considered an indication for biocompatibility. RESULTS: Catalase diffused across the nanoporous membrane counteracted the cytotoxic effect of hydrogen peroxide on HREC. We also found that vitamin C, acting directly or after diffusion across the filter, up to concentrations physiologically present in the eye, was a concentration dependent modulator of HREC's ability to survive and sprout. Additionally, we confirmed the ability of endostatin to block the growth of HREC either attached or sprouting from cell aggregates, after diffusion across the Anopore nanofilter. CONCLUSIONS: The drug delivery method based on the administration of angiostatic and antioxidant agents across the inorganic aluminum oxide nanoporous filter passed the key in vitro tests for diffusibility and biocompatibility, opening the way for medical applications.