laponite and Disease-Models--Animal

In the present investigation, we have synthesized the dalteparin which is a kind of low molecular weight heparin (LMWH) and possess the antitumor and antiangiogenic efficacy with carboxylates poloxamer 407 to form a heparin-poloxamer nanogel (HP copolymer). The complex HP is capable of enhancing the efficacies, minimizing the side effects of dalteparin and exhibiting a good thermosensitivity. Therewith, the synthetic Laponite RDS (LR) nanosilicate embarked with doxorubicin (DOX) at a satisfactory high drug entrapment efficiency was integrated with the complex HP and thus constituted a newfangled biocompatible injectable temperature-sensitive hydrogel. To our delight, consociation with 2.5 w/v % of LR nanodisks, HP at the concentration of 5 w/v % was sufficient to execute the solution-gel transition at animal heat, while 17.5 w/v % of P-407 was needed for fabricating the LR-P hydrogel. Simultaneously, LR-HP possesses a more preferable syringeability. Furthermore, the release behavior in vitro for the DOX@LR-HP demonstrated as extended and controlled manner, wherein, the drug-eluting profile was regulated by the LR nanocomposites. Moreover, based on synergic action of heparin and drug, DOX@LR-HP hydrogels demonstrated the best antitumor efficacy in vitro and in vivo. What is noteworthy is that through the course of treatment, the reflected anticancer efficacy direct at the established xenograft S180 sarcoma tumor was provided by the single administration of the DOX@LR-HP hybrid gel. This excellent long-term sustainable-anticancer function in vivo demonstrating the prospect of this nanohybrid-gel combination as an estimable focal drug delivery vehicle for treatment of cancer.

Topics: Animals; Antineoplastic Agents; Disease Models, Animal; Drug Delivery Systems; Drug Liberation; Female; Heparin, Low-Molecular-Weight; Humans; Hydrogels; Mice; Nanoparticles; Poloxamer; Rheology; Silicates; Spectrum Analysis; Temperature; Theranostic Nanomedicine; Thermogravimetry; Xenograft Model Antitumor Assays

To study the safety and biocompatibility of Laponite clay (LAP) within an intravitreal and suprachoroidal administration in rabbit eyes.. Thirty-two New Zealand albino rabbits were divided into two experimental groups to test intravitreal (IVT group) and suprachoroidal (SCS group) administration of a 100-μl and 50-μl Laponite suspension respectively. Following injection, the eyes were monitored by ocular tonometry, slit-lamp eye examination and indirect ophthalmoscopy, at 24 h, 1, 4, 12, and 14 weeks post administration. Histological examination was also performed to determine whether any ocular pathological change had occurred. Throughout the study, LAP presence in vitreous was estimated by complexometric titration with ethylenediaminetetraacetic acid (EDTA), taking advantage of the Laponite high content of magnesium ions.. Neither significant differences in the intraocular pressure, nor relevant ocular complications were found in the two experimental groups after LAP administration. The histology of the retina remained unchanged. LAP presence in vitreous could be indirectly confirmed by complexometric titration until 14 weeks post administration in eyes of IVT group.. Laponite could be considered as a vehicle for potential clinical use in ocular drug administration, due to its proven ocular biocompatibility and its transparency in gel state.

Topics: Aluminum Silicates; Animals; Biocompatible Materials; Clay; Disease Models, Animal; Electroretinography; Female; Intravitreal Injections; Ophthalmoscopy; Rabbits; Retina; Retinal Diseases; Silicates; Vision, Ocular