Novel biomimetic nanostructured lipid carriers for cancer therapy: preparation, characterization, and in vitro/in vivo evaluation.

Nanostructured lipid carriers (NLC) have become a research hotspot, wherein cancer-targeting effects are enhanced and side effects of chemotherapy are overcome. Usually, accelerated blood clearance (ABC) occurs after repeated injections, without changing the immunologic profile, despite PEGylation which prolongs the circulation function. To overcome these problems, we designed a red blood cell-membrane-coated NLC (RBCm-NLC), which was round-like, with a particle size of 60.33 ± 3.04 nm and a core-shell structure. Its stability was good, the drug paclitaxel (PTX) release from RBCm-PTX-NLC was less than 30% at pH7.4 and pH6.5, and the integrity of RBC membrane surface protein was maintained before and after preparation. Additionally, in vitro assays showed that, with the RBCm coating, the cellular uptake of the NLC by cancer cells was significantly enhanced. RBCm-NLC can avoid recognition by macrophage cells and prolong circulation time in vivo. In S180 tumor-bearing mice, the DiR-labeled RBCm-NLC group showed a stronger fluorescence signal and longer retention in tumor tissues, indicating a prompt tumor-targeting effect and extended blood circulation. Importantly, RBCm-PTX-NLC enhanced the antitumor effect and extended the survival period significantly in vivo. In summary, biomimetic NLC offered a novel strategy for drug delivery in cancer therapy.

Chemotaxis-driven delivery of nano-pathogenoids for complete eradication of tumors post-phototherapy.

The efficacy of nano-mediated drug delivery has been impeded by multiple biological barriers such as the mononuclear phagocyte system (MPS), as well as vascular and interstitial barriers. To overcome the abovementioned obstacles, we report a nano-pathogenoid (NPN) system that can in situ hitchhike circulating neutrophils and supplement photothermal therapy (PTT). Cloaked with bacteria-secreted outer membrane vesicles inheriting pathogen-associated molecular patterns of native bacteria, NPNs are effectively recognized and internalized by neutrophils. The neutrophils migrate towards inflamed tumors, extravasate across the blood vessels, and penetrate through the tumors. Then NPNs are rapidly released from neutrophils in response to inflammatory stimuli and subsequently taken up by tumor cells to exert anticancer effects. Strikingly, due to the excellent targeting efficacy, cisplatin-loaded NPNs combined with PTT completely eradicate tumors in all treated mice. Such a nano-platform represents an efficient and generalizable strategy towards in situ cell hitchhiking as well as enhanced tumor targeted delivery.

Cancer cell membrane-coated mesoporous silica loaded with superparamagnetic ferroferric oxide and Paclitaxel for the combination of Chemo/Magnetocaloric therapy on MDA-MB-231 cells.

To effectively inhibit the growth of breast cancer cells (MDA-MB-231 cells) by the combination method of chemotherapy and magnetic hyperthermia, we fabricated a biomimetic drug delivery (CSiFePNs) system composed of mesoporous silica nanoparticles (MSNs) containing superparamagnetic ferroferric oxide and Paclitaxel (PTX) coated with MDA-MB-231 cell membranes (CMs). In the in vitro cytotoxicity tests, the MDA-MB-231 cells incubated with CSiFePNs obtained IC50 value of 0.8 µgL-1, 3.5-fold higher than that of SiFePNs. The combination method of chemotherapy and magnetic hyperthermia can effectively inhibit the growth of MDA-MB-231 cells.

A Biomimetic Gold Nanocages-Based Nanoplatform for Efficient Tumor Ablation and Reduced Inflammation.

Gold nanocages (AuNCs), with high photothermal conversion efficiency and unique hollow interiors, have become a promising nanoplatform for synergistic phototheraml therapy (PTT)-chemotherapy. However, the insufficient tumor targeting, in vivo premature drug leakage and low drug loading efficiency responsible for the spatial-temporal un-synchronization of PTT-chemotherapy, as well as inflammatory response might compromise the anticancer treatment of AuNCs-based drug delivery systems. Methods: Cancer cell membrane (CCM)-coated AuNCs were developed to load anticancer drug doxorubicin (DOX@CAuNCs) by transmembrane ammonium sulfate gradient method. In vitro and in vivo analysis, including characterization, macrophage phagocytosis and tumor targeting capacity, near-infrared (NIR) laser-induced drug release, antitumor efficacy and inflammation response were systematically performed. Results: DOX@CAuNCs showed a high DOX loading capacity and on-demand NIR laser-triggered DOX release compared with CAuNCs passively loading DOX by electrostatic adsorption, a commonly used method to load drug to AuNCs. Meanwhile, in view of the properties of CCM coated on AuNCs, DOX@CAuNCs exhibited decreased macrophage phagocytosis, prolonged blood circulation and enhanced internalization by cancer cells, generating preferable tumor targeting ability. With these integrated advantages, DOX@CAuNCs demonstrated highly efficient and precise spatial-temporal synchronization of PTT-chemotherapy, achieving complete tumor ablation with no obvious side effects. Besides, coating with CCM significantly alleviated AuNCs-induced inflammatory response. Conclusion: This biomimetic AuNCs-based platform might be a prospective drug delivery system for precision PTT and chemotherapy, acquiring desired cancer treatment efficacy and low inflammatory response.

Effects of new biomimetic regenerating agents on corneal wound healing in an experimental model of post-surgical corneal ulcers.

OBJECTIVE: The purpose of this study is to assess the effectiveness of the topical application of cacicol regenerating agent (RGTA) in an experimental model of corneal ulcer after photorefractive keratectomy (PRK) in mice. METHODS: Mice were subjected to PRK surgery with a 2.0mm ablation zone on the central cornea and 45mm of depth on a VISX Star S2 excimer laser. Corneas were treated topically with cacicol drops 1hour and 48hours after injury. Control groups received balanced salt solution (BSS) in the same dosage. Clinical and histopathological events were evaluated at 1, 2, 3 and 7 days after surgery. Sections obtained through the central region of the corneas were used to analyze the histopathological events of injured and healed corneas. αSMA (myofibroblast transformation), E cadherin (assembly of epithelial cells) and neuronal class III ß-tubulin (innervation) were performed. RESULTS: Corneas treated topically with cacicol for 7 days showed a greater degree of transparency compared to controls. cacicol treated corneas showed improved epithelial cytoarchitecture. Analysis of αSMA profiles in the stroma showed that cacicol reduced or delayed the presence of myofibroblasts in the stroma compared to BSS (P<0.001). Finally, a putative neuroregenerative effect of cacicol was found in corneas subjected to an experimental PRK lesion. In some cases some interindividual variability could be observed due to the design of the experimental model. This is a limitation to consider, despite the statistical significance of the data. CONCLUSIONS: In a model of laser induced surgical lesions in the cornea, topical application of an RGTA (i.e. cacicol) could be involved in avoiding myofibroblast scarring formation and promoting nerve regeneration.

Evaluation of effects of topic melatonin on implant surface at 5 and 8 weeks in Beagle dogs.

PURPOSE: The aim of this study was to evaluate the effect of the topical application of melatonin on osteointegration of dental implants in Beagle dogs 5 and 8 weeks after their insertion. MATERIALS AND METHODS: For subsequent insertion of dental implants, upper and lower premolars and molars were extracted from 12 Beagle dogs. Each mandible received cylindrical screw implants of 3.25 mm in diameter and 10 mm in length. The implants were randomly assigned to the mesial and distal sites on each side of the mandible. Prior to implanting, 1.2 mg lyophylized powder melatonin was applied to one bone hole at each side of the mandible. None was applied at the control sites. Eight histological sections per implant were obtained for histomorphometric studies. RESULTS: After 5- and 8-week treatment periods, melatonin significantly increased the inter-thread bone (p < 0.05) and new bone formation (p < 0.05) in comparison to control implants in both weeks. There were no significant increases in the bone-to-implant contact and peri-implant bone (p > 0.05). CONCLUSION: Topical application of melatonin may act as a biomimetic agent in the placement of endo-osseous dental implants at 5 and 8 weeks after the implantation.

Biomimetic actinide chelators: an update on the preclinical development of the orally active hydroxypyridonate decorporation agents 3,4,3-LI(1,2-HOPO) and 5-LIO(Me-3,2-HOPO).

The threat of a dirty bomb or other major radiological contamination presents a danger of large-scale radiation exposure of the population. Because major components of such contamination are likely to be actinides, actinide decorporation treatments that will reduce radiation exposure must be a priority. Current therapies for the treatment of radionuclide contamination are limited and extensive efforts must be dedicated to the development of therapeutic, orally bioavailable, actinide chelators for emergency medical use. Using a biomimetic approach based on the similar biochemical properties of plutonium(IV) and iron(III), siderophore-inspired multidentate hydroxypyridonate ligands have been designed and are unrivaled in terms of actinide-affinity, selectivity, and efficiency. A perspective on the preclinical development of two hydroxypyridonate actinide decorporation agents, 3,4,3-LI(1,2-HOPO) and 5-LIO(Me-3,2-HOPO), is presented. The chemical syntheses of both candidate compounds have been optimized for scale-up. Baseline preparation and analytical methods suitable for manufacturing large amounts have been established. Both ligands show much higher actinide-removal efficacy than the currently approved agent, diethylenetriaminepentaacetic acid (DTPA), with different selectivity for the tested isotopes of plutonium, americium, uranium and neptunium. No toxicity is observed in cells derived from three different human tissue sources treated in vitro up to ligand concentrations of 1 mM, and both ligands were well tolerated in rats when orally administered daily at high doses (>100 micromol kg d) over 28 d under good laboratory practice guidelines. Both compounds are on an accelerated development pathway towards clinical use.