Genetic deletion of the Tas2r143/Tas2r135/Tas2r126 cluster reveals that TAS2Rs may not mediate bitter tastant-induced bronchodilation.

Bitter taste receptors (TAS2Rs) and their signaling elements are detected throughout the body, and bitter tastants induce a wide variety of biological responses in tissues and organs outside the mouth. However, the roles of TAS2Rs in these responses remain to be tested and established genetically. Here, we employed the CRISPR/Cas9 gene-editing technique to delete three bitter taste receptors-Tas2r143/Tas2r135/Tas2r126 (i.e., Tas2r triple knockout [TKO]) in mice. The fidelity and effectiveness of the Tas2r deletions were validated genetically at DNA and messenger RNA levels and functionally based on the tasting of TAS2R135 and TAS2R126 agonists. Bitter tastants are known to relax airways completely. However, TAS2R135 or TAS2R126 agonists either failed to induce relaxation of pre-contracted airways in wild-type mice and Tas2r TKO mice or relaxed them dose-dependently, but to the same extent in both types of mice. These results indicate that TAS2Rs are not required for bitter tastant-induced bronchodilation. The Tas2r TKO mice also provide a valuable model to resolve whether TAS2Rs mediate bitter tastant-induced responses in many other extraoral tissues.

The feasibility and safety of biomaterials for posterior scleral reinforcement in rabbits.

To explore the feasibility and safety of biomaterials for posterior scleral reinforcement (PSR) in rabbits. Decellularization and genipin crosslink were applied to the fresh bovine pericardium and porcine endocranium, and then mechanical properties, suture retention strength, and stability were tested. PSR operation was performed on 24 rabbit eyes using treated biological materials. Ophthalmic examination was performed regularly before and after PSR operation (1 week, 1 month, 3 months, 6 months). To evaluate the effectiveness, A ultrasound, diopter, and optical coherence tomography were conducted. General condition, fundus photograph, and pathological examination were recorded to evaluate the safety. Compared with genipin crosslinked bovine pericardium (Gen-BP) (21.29 ± 13.29 Mpa), genipin crosslinked porcine endocranium (Gen-PE) (34.85 ± 3.67 Mpa,P< 0.01) showed a closer elastic modulus to that of genipin crosslinked human sclera. There were no complications or toxic reactions directly related to the materials. Capillary hyperplasia, inflammatory cell infiltration, and collagen fiber deposition were observed, and the content of type I collagen fibers increased after PSR. Overall, the choroidal thickness of treated eyes was significantly thickened at different time points after PSR, which were 96.84 ± 21.08 µm, 96.72 ± 22.00 µm, 90.90 ± 16.57 µm, 97.28 ± 14.74 µm, respectively. The Gen-PE group showed changes that were almost consistent with the overall data. Gen-BP and Gen-PE are safe biological materials for PSR. The Gen-PE group demonstrated more significant advantages over the Gen-BP group in terms of material properties.

Air tamponade in vitrectomies for primary rhegmatogenous retinal detachment caused by superior breaks.

The effectiveness of filtered air tamponade for superior retinal breaks was well established. This study was performed to compare the treatment efficacy of pars plana vitrectomies (PPV) with filtered air and silicone oil (SO) for patients with rhegmatogenous retinal detachment (RRD) caused by superior breaks with no or mild proliferative vitreoretinopathy. Patients of RRD with superior breaks who underwent PPV with filtered air (Group A) and SO (Group S) tamponade were reviewed retrospectively. Age, gender, laterality, lens status, duration of symptoms, macular status, proliferative vitreoretinopathy grade, use of perfluorocarbon liquid, early and late postoperative complications, follow-up duration were acquired. The primary anatomic reattachment after the first surgery and the final rate of successful reattachment was compared as the main outcome. Secondary outcomes were long-term postoperative best-corrected visual acuity (BCVA), rate of deferred cataract removal, surgical complications and total surgery number. The primary anatomic success rate was 88% (14/16 eyes) in Group A and 100% (16/16 eyes) in group S, which was not significantly different (P = .484). Both groups achieved 100% final anatomic success. The rate of cataract removal was 57.1% and 100% (P = .016), and the duration from first surgery to cataract surgery was 231.38 ±â€…241.23 and 156.36 ±â€…110.09 days (P = .428) for group A and group S, respectively. The rate of postoperative epiretinal membrane was 21.4% vs 25.0% (P = 1.000). Postoperative BCVA was associated with preoperative BCVA after multiple linear analysis. The primary and final anatomic success rate for PPV with air tamponade and SO in treating RRD with superior breaks were not statistically different. The rate of deferred cataract removal was higher in patients with SO as tamponade.

Novel SN38 derivative-based liposome as anticancer prodrug: an in vitro and in vivo study.

BACKGROUND: Many novel drug delivery systems have been extensively studied to exploit the full therapeutic potential of SN38, which is one of the most potent antitumor analogs of camptothecins (CPTs), whose clinical application is seriously hindered by poor water solubility, low plasmatic stability, and severe toxicity, but results are always unsatisfactory. METHODS: In this study, combining the advantages of prodrug and nanotechnology, a lipophilic prodrug of SN38, SN38-PA, was developed by conjugating palmitic acid to SN38 via ester bond at C10 position, and then the lipophilic prodrug was encapsulated into a long-circulating liposomal carrier by film dispersion method. RESULTS: The SN38-PA liposomes were characterized as follows: an average particle size of 80.13 nm, an average zeta potential of -33.53 mv, and the entrapment efficiency of 99%. Compared with CPT-11, SN38-PA liposome was more stable in close lactone form, more efficient in conversion rate to SN38, and more potent in cytotoxicity against tumor cells. Pharmacokinetic study showed that SN38-PA liposome had significantly enhanced plasma half-life (t1/2) value of SN38 and increased area under the curve (AUC) of SN38, which was 7.5-fold higher than that of CPT-11. Biodistribution study showed that SN38-PA liposome had more active metabolite SN38 in each tissue. Finally, the pharmacodynamic study showed that SN38-PA liposome had higher antitumor effect with the antitumor inhibition rate of 1.61 times than that of CPT-11. CONCLUSION: These encouraging data merit further investigation on this novel SN38-PA liposome.

An optimized two-vial formulation lipid nanoemulsion of paclitaxel for targeted delivery to tumor.

The discovery of new intravenous drug delivery carrier for water-insoluble drug is a challenging task. In this paper, novel two-vial formulation of paclitaxel (PTX)-loaded lipid nanoemulsions (TPLEs) with particle sizes of 110nm (TPLE-1), 220nm (TPLE-2) and 380nm (TPLE-3), which were formed by mixing a PEG400 solution of PTX and 10% (w/w) blank lipid emulsions (BLEs) with different particle size prior to use, were developed and comparatively evaluated for their pharmaceutics, pharmacokinetics, biodistribution, in vitro and in vivo anticancer efficiency. Among them, TPLE-1 displayed higher PTX-loading, slower PTX-release and larger PTX-distribution in oil-phase, significantly reduced extraction by RES organs, increased tumor-uptake, showed stronger cytotoxicity against MCF-7 cells and more potent anticancer efficacy on MCF-7 tumor-bearing nude mice, and had greater plasma AUC0-∞ value, smaller plasma clearance (CL), longer mean residence time (MRT) and elimination half-life (T1/2) in SD rats. It also exhibited the same in vivo efficacy as Taxol® and even produced less hemolysis and intravenous irritation. Moreover, its LD50 was 4.3-fold higher than that of Taxol®. All results demonstrate that TPLE-1 is a promising candidate drug due to its high tumor-accumulation and effectiveness, low toxicity, good safety and druggability in clinical application for the cancer therapy.