Topical treatment of corneal alkali burns with Gly-thymosin ß4 solutions and in situ hydrogels via inhibiting corneal neovascularization and improving corneal epidermal recovery in experimental rabbits.

AIM: Corneal alkali burns are a severe disease and commonly encountered in the emergent clinic. A rapid medical treatment for the burn is very important. Gly-thymosin ß4 (Gly-Tß4) is a biomimic derivative of natural thymosin ß4. The aim of this study is to evaluate the corneal recovery effects of Gly-Tß4 topical therapy on alkali burns in rabbit corneas. METHODS: Rabbit alkali burns were induced with NaOH-contained filter paper. Phosphate-buffered solutions at pH 7.0, Gly-Tß4 solutions, blank in situ hydrogels, and Gly-Tß4in situ hydrogels were dropped on the burned corneas. The treatments were continued for 14 days. Conjunctiva hyperemia, corneal edema, intraeye extravasation, hemorrhaging, corneal neovascularization (CNV), and corneal opacity were observed. Corneal immunohistochemistry and histopathology were performed. RESULTS: Gly-Tß4 solutions led to a lower corneal burn index than the other regimens. Hydrogels may stimulate the burned corneas due to the direct contact of them, and prevent the rapid release of Gly-Tß4. Gly-Tß4 significantly inhibited CNV according to the images of the corneas, CNV areas, and CD31 expression. Furthermore, Gly-Tß4 improved corneal epidermal recovery according to the histopathological result. CONCLUSION: Gly-Tß4 solutions are a promising formulation for topical treatment of corneal alkali burns.

[Thrombocytopoietic Efficacy of Pegylated Recombinant Human Interleukin-11 Mutein in Myelosuppressed Mice].

OBJECTIVE: To evaluate the effect of PEGylated IL-11 mutein (PEG-mIL 11) with different dose or injection frequency on thrombocytopenia in myelosuppressed mice and to compare its effect with mIL-11, so as to provide reference data for clinical use. METHODS: Myelosuppressive model with thrombocyopenia was produced in BALB/c mice by whole body 60Co γ-ray irradiation in dose of administration 2.5 Gy followed by i.p. injections of carboplatin at 50 mg/kg. In study of injection frequency, 30 thrombocytopenic BALB/c mice were randomly divided into 5 groups: vehicle control group (once daily on d1, 4, 7), mIL-11 group [200 µg/(kg·d)×9 d], PEG-mIL 11 A group [111800 µg/(kg·d)×1 d (d 1)], PEG-mIL 11 B group 900 µg/(kg·d)×2 d (d 1,5), and PEG-mIL 11 C group [600 µg/(kg·d)×3 d (d 1,4,7)]. The route of administration is subcutaneous injection. The platelet counts were monitored in the subsequant 5 weeks. In study of dose administration, 100 thrombocytopenic BALB/c mice were randomly divided into 5 groups: vehicle control group (once daily on d1 and 5), mIL-11 group 200 µg/(kg·d)×9 d, and PEG-mIL 11 low-, mid-, and high-dose groups (200, 420 and 900 µg/(kg·d)×2 d, once a day on d1 and 5). The route of administration is subcutaneous injection. The platelet counts were monitored every 2-3 days in the subsequant 5 weeks, and CFU-Meg was determined on d 8 of the bone marrow cells collection. RESULTS: After 60Co irradition and carboplatin injection, Plt level decreased with time, and a >80% reduction was noted at nadir when comparing with baseline. In frequency of administration study, the platelet nadir of the 3 PEG-mIL 11 groups were significantly higher than that of vehicle control and mIL-11 groups (P<0.05), while no significant difference was noted among the 3 groups of different administration frequences; In dose level study, the reduction of Plt count at the nadir in the 3 PEG-mIL 11 groups was significantly less than that of vehicle control and mIL-11 groups (P<0.05). And a rapid recovery of Plt count was found in the PEG-mIL 11 groups with a dose-dependent increase of Plt count on d 10. A lower reduction and a rapider recovery of RBC was also found in the PEG-mIL 11 groups. No significant effect on WBC was found for all the treatment groups. An increase in CFU-Meg was observed in PEG-mIL 11 and mIL-11 groups, with higher CFU-Meg in PEG-mIL 11 groups. CONCLUSION: A preventive effect of PEG-mIL 11 on thrombocytopenia in myelosuppressed mice has been confirmed. In comparison with mIL-11, a better effect of PEG-mIL 11 is obtained under lower dose frequency, indicating a better compliance of the treatment regimen, and providing a foundation for developing a long-acting preparation of rhIL-11.

LHRH-PE40 fusion protein tethered silica nanorattles for imaging-guided tumor-specific drug delivery and bimodal therapy.

Docyanine green (ICG) and LHRH-PE40 fusion protein are tethered onto drug carriers of silica nanorattles for imaging-guided tumor-specific drug delivery and bimodal therapy. The synergistic therapeutic effect of toxin PE40 and the chemotherapeutic drug docetaxel (Dtxl), specifically directed by LHRH to cancer, improves cancer treatment. Simultaneously, ICG enables real-time monitoring of the silica nanocomposites and therapeutic response.

Production and characterization of highly purified recombinant thymosin beta 4 in Escherichia coli.

Thymosin ß4 (Tß4) is a small peptide composed of 43 amino acids. It has many important biological functions, such as promoting cardiac repair and wound healing, and therefore has great potential in clinical applications. In this report, we describe a novel and efficient way to produce highly purified and active Tß4. It was expressed in a soluble form using a DsbA and hexahistindine tag in Escherichia coli (E. coli). Using high cell density cultivation, the final biomass concentration was about 50 g L(-1) dry cell weight with the expression level of the fusion protein being 40%. To obtain highly purified protein, a purification process involving a five-step column procedure was implemented. The purity of Tß4 was above 98% and all the host cell related impurities, such as endotoxin, host cell protein and residual DNA levels, were within the permissible range listed in the Chinese Pharmacopoeia. The E-rosette test demonstrated that the bioactivity of purified Tß4 was consistent with other published work. This is the first report producing highly purified Tß4 from genetically engineered sources.

Size-dependent endocytosis of single gold nanoparticles.

Herein we investigate the size-dependent force of endocytosing single gold nanoparticles by HeLa cells. The results reveal that both the uptake and unbinding force values are dependent upon the size of gold nanoparticles.

[Expression of laminin 5 in rat skin wounds regulated by recombinant thymosin beta4].

OBJECTIVE: To explore the mechanism of recombinant thymosin beta4 (Tbeta4) accelerating skin wound healing in rats by regulating laminin 5 expression. METHODS: Two full thickness 8 mm punch wounds were made at the costovertebral angle on dorsal surface of each adult male rats weighing 200-250 g. Sixty rats were randomized into the control group (n = 15) and the experimental group (n = 45), which was subdivided into low, medium and high dose groups (n = 15). Tbeta4 was applied topically at 2, 6, 18 microg in 50 microL PBS for every 12 hours after model making in the experimental group. The identical amounts of phosphate buffered saline was applied in the control group. Wound healing was observed after model making and immunohistochemical observation was conducted 2, 4 and 7 days after operation. RESULTS: Seven days after operation, wound contracted obviously and most of the wounds connected well with the margin. In the control group, low dose group, medium dose group and high dose group, the wound healing rate were 7.67% +/- 5.46%, 29.01% +/- 7.43%, 26.54% +/- 11.49% and 10.39% +/- 3.96% respectively 2 days after operation; 28.16% +/- 13.76%, 37.99% +/- 13.05%, 42.00% +/- 9.56% and 39.58% +/- 12.74% respectively 4 days after operation; 59.08% +/- 19.02%, 64.15% +/- 17.92%, 77.39% +/- 8.45% and 69.78% +/- 8.45% respectively 7 days after operation. At 2 days after operation, significant differences were notified in healing rats between 3 sub-experimental groups and the control group (P < 0.05). Immunohistochemistry staining showed that there was a little more positive expression of laminin 5 2 days after operation that beneficial to promote the proliferation and differentiation of cell in every group, including positive cells and ECM. But in medium group there was fewer expression, only at the borderline and bottom of the wound, while the expression significantly increased 4 days after operation (P < 0.05) and there was a relative high expression 7 days after operation (P < 0.01). CONCLUSION: Tbeta4 can inhibit the expression of laminin 5 early, and then up-regulate laminin 5 expression to moderate the reformation of ECM, promote the migration of epidemic cell and accelerate skin wound healing.