Design and optimization of thermosensitive nanoemulsion hydrogel for sustained-release of praziquantel.

OBJECTIVE: This work aimed to develop an alternative sustained-release thermosensitive praziquantel-loaded nanoemulsion (PZQ-NE) hydrogel for better schistosomiasis treatment. SIGNIFICANCE: PZQ-NE-dispersed chitosan/glycerol 2-phosphate disodium/HPMC (NE/CS/ß-GP/HMPC) hydrogel was successfully prepared to improve bioavailability of PZQ. METHODS: Solubility tests and pseudo-ternary phase diagrams were applied to screen optimal oils, surfactants and co-surfactants of NE. The hydrogels were characterized for gelling time, surface exudates, rheological properties and in vitro drug release. Formulation optimization of NE/CS/ß-GP/HMPC hydrogel was conducted by Box-Behnken experimental design combined with response surface methodology. In vitro cytotoxicity of hydrogel was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. The sustained-release property of PZQ in NE and optimized hydrogel was evaluated by pharmacokinetic study in rabbits. RESULTS: The formulation of PZQ-NE consisted of mass ratio of 12.5% capryol 90 containing PZQ (160 mg/g), 40% cremophor RH 40/tween 20 and transcutol HP (S/CoS = 2:1), 47.5% deionized water. PZQ releasing from NE/CS/ß-GP/HMPC hydrogels was best fitted to Higuchi model and governed by diffusion. Rheological investigation evidenced the themosensitive gelation of different hydrogel systems and their gel-like character at 37 °C. The optimized hydrogel formulation consisted of HPMC solution (103.69 mg/g), 3.03% (w/v) chitosan and 14.1% (w/v) ß-GP showed no cytotoxicity when the addition of NE was no more than 100 mg/g. Pharmacokinetic parameters indicated that NE/CS/ß-GP/HMPC hydrogel can significantly slow down drug elimination, prolong mean residence time and improve bioavailability of PZQ. CONCLUSIONS: NE/CS/ß-GP/HMPC hydrogel possessed sustained-release property and could be an alternative antischistosomal drug delivery system with improved therapeutic effect.

Cholesterol-lowering effects of rhubarb free anthraquinones and their mechanism of action.

Rhubarb free anthraquinones (RhA) have significant lipid-regulating activity. However, whether RhA monomers have a role in lipid-regulating and their mechanism of action remains unclear. Based on the cholesterol accumulated HepG2 cell model, the cholesterol-regulating effect of RhA monomers and their combinations was investigated. The expression of sterol-regulatory element binding protein 2 (SREBP2), 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR) and squalene monooxygenase (SQLE) of the model cells was analyzed to preliminarily explore the mechanism of action. After that, the liposomes of each active RhA monomer were separately prepared with the same lipid materials and the same preparation method so that each monomer has similar or equal bioavailability after oral administration to rats. Finally, the hypercholesterolemic rat model was established, and the effect of active RhA monomers loaded liposomes as well as their combinations on cholesterol-regulating was investigated and their mechanism of action was analyzed. The results showed that aloe-emodin, rhein and emodin were the main cholesterol-regulating components of RhA, and the combination of rhein and emodin showed significant cholesterol-lowering effect, which may be related to the expression of SREBP2, HMGCR and SQLE in the rat liver.

Combination of oxaliplatin and POM-1 by nanoliposomes to reprogram the tumor immune microenvironment.

Some chemotherapy can damage tumor cells, releasing damage-related molecular patterns including ATP to improve immunological recognition against the tumor by immunogenic cell death (ICD). However, the immune-stimulating ATP may be rapidly degraded into immunosuppressive adenosine by highly expressed CD39 and CD73 in the tumor microenvironment, which leads to immune escape. Based on the above paradox, a liposome nanoplatform combined with ICD inducer (oxaliplatin) and CD39 inhibitor (POM-1) is designed for immunochemotherapy. The liposomes efficiently load the phospholipid-like oxaliplatin prodrug, and the cationic charged surface could adsorb POM-1. Rationally designed DSPE-PEGn-pep, on the one hand, could cover and hide POM-1 to avoid systematic toxicity and, on the other, achieve a response and charge reversal to favor POM-1 shedding and tumor deep penetration. This combination maximizes the ICD effect, and takes two-pronged advantage of stimulating the immune response and relieving immune suppression. The designed POL can effectively inhibit the growth of in situ, lung metastasis and postoperative recurrence melanoma model and form long-term immune memory. With the powerful clinical transformation potential of nanoliposome platforms, this new synergistic strategy is expected to enhance anticancer effects safely and effectively.

Research in Tissue Engineering Scaffold Materials for Alveolar Bone Repair.

An increasing number of scaffold materials are available for repairing alveolar bone defects. As each material has its own advantages and disadvantages, these characteristics should be carefully considered. This paper presents a review of the currently available materials for repairing alveolar bone defects, including artificial ceramics, polymers, and metals. The combination of seed cells or growth factors with these materials is the future trend for the treatment of alveolar bone defects. In this study, a comprehensive analysis of the advantages, disadvantages, and development status of various materials is carried out, providing a basis for future material selection.

Preparation of BMP-2 loaded MPEG-PCL microspheres and evaluation of their bone repair properties.

Autologous or allogeneic bone grafts are common methods to treat bone defects. Bone tissue engineering combining carrier material with the active factor can induce a generation of new bone at the bone defect site. However, its clinical application is restricted by the limited donors, the high morbidity at the donor site, the low activity in vivo, and dose-independent adverse effect. To overcome the limitations of traditional therapies, it is urgent to find and develop a repair material that can replace natural bones. Hence, we designed and prepared suitable MPEG-PCL microspheres loaded bone morphogenetic protein-2 (BMP-2/MPEG-PCL-MS) to effectively solve the problem mentioned above, prolong its reaction time at the targeted site, and avoid the pain of patients caused by frequent administration. The physicochemical properties and in vitro release behaviors were good. The microspheres showed high biocompatibility and strongly induced osteogenesis in vivo. BMP-2/MPEG-PCL-MS has been proven to exert sustained-release in vivo and maintain the inherent BMP-2 activity. They can be directly injected into the bone defect site, or implanted to a large bone defect site together with stent material to exert therapeutic effects. Hence, this smart drug delivery system has promising potential for clinical applications and provides a well-controlled design for combination of tissue engineering and pharmaceutics for further exploration.

Ethosomal Gel for Improving Transdermal Delivery of Thymosin ß-4.

PURPOSE: Thymosin ß-4(Tß-4) is a macromolecular protein drug with potential for drug development in wound repair but is limited by the shortcomings of macromolecular protein, such as large volumes, poor membrane permeability, and unstable physicochemical characteristics. Ethosomes could enhance cell membrane fluidity and reduce epidermal membrane density to make macromolecular drugs through the stratum corneum into the deeper layers of the skin easily. Herein, we developed and characterized a novel transdermal delivery vehicle to load macromolecular protein peptides and use Tß-4 as a model drug wrapped into ethosomes. METHODS: We used the orthogonal method to optimize the formulation of the ethosome preparation prepared by the ethonal infusion method. Ethosomal gels were characterized by using different analytical methods. Transdermal release rate in vitro have been demonstrated in Franz diffusion cells and the efficacy of drug-loaded nanocarriers in vivo was investigated in a mouse model. RESULTS: Optimized Tß-4 ethosomal gels have good physicochemical properties. The drug amounts of the cumulative release in the ethosomal gel within 5 hours were 1.67 times that of the T-ß4 gel in vitro release study, and the wound healing time of ethosomal gel group was only half of the T-ß4 gel group in vivo pharmacokinetic study. Compared with the free drug group, the ethosome preparation not only promotes the percutaneous absorption process of the macromolecular protein drugs but also shortened wound recovery time. CONCLUSION: Hence, we provide a possible good design for ethosomal gel system that can load macromolecular protein peptide drugs to achieve transdermal drug administration, promoting the percutaneous absorption of the drug and improving the effect.

Nanotechnology-mediated immunochemotherapy combined with docetaxel and PD-L1 antibody increase therapeutic effects and decrease systemic toxicity.

Immunotherapy has exhibited enormous practice in the treatment of melanoma because of the intrinsic properties of tumor. Tumor can downmodulate immune function via multiple mechanisms such as immune checkpoint pathways. The PD-L1 monoclonal antibodies that block the PD1/PD-L1 pathway, which induced tumor cells to evade an immune attack, can delay tumor growth efficiently with inevitable disadvantages such as low selectivity and systemic toxicity. Nanomedicine is clearly an approach that holds tremendous potential for addressing the shortcomings and assisting delivery of drugs with proper biodistribution. Herein, we developed a smart nanoplatform with precisely active targeting liposome co-loaded chemotherapy and immunotherapy drugs for synergistic antitumor effects while decreasing systemic toxicity. Immunoliposomes have stable pharmaceutical properties and show a significant antitumor effect in vivo and in vitro. Cellular uptake in vitro and biodistribution in vivo demonstrated that immunoliposomes could be delivered and accumulated more in tumor tissues. These immunoliposomes exhibited effective tumor inhibition and prolonged survival time due to activation of tumor-specific CD8+ T cell and highly selective tumor killing. In addition, safety evaluation of liposomes also demonstrated their increased tumor accumulation and decreased systemic toxicity. Hence, this smart pH-sensitive nanoplatform has promising potential for clinical applications and possibly provides a well-controlled design for combination of chemotherapy with various immunotherapies for further exploration.

A novel controlled drug delivery system based on alginate hydrogel/chitosan micelle composites.

In this study, we present a novel cross-linked unimolecular micelle based on chitosan. For controlling drug delivery via oral administration, emodin (EMO) encapsulated micelles were loaded into sodium alginate hydrogel matrix to construct the pH-sensitive hydrogel/micelle composites. The optimized formulation of micelle that consists of 8.06% CaCl2, 1.71% chitosan and 26.52% ß-GP was obtained by the combination of Box-Behnken experimental design and response surface methodology. The morphological analysis showed that the micelles exhibited a smaller diameter of about 80nm in aqueous solution, but dilated to 100-200nm in hydrogel owing to the formation of polyelectrolyte complexes. The physical characteristics in simulated digestive fluids were investigated, demonstrating that the ratio of hydrogel to micelle distinctly affected swelling, degradation and in vitro drug release behaviors. The hydrogel/micelle (1:1) exhibited a sustained-release profile, while hydrogel/micelle (3:1) exhibited a colon-specific profile. Their corresponding release mechanisms revealed that the release of drug from these two formulations followed a complex process, in which several mechanisms were involved or occurred simultaneously. These results demonstrated that the pH-sensitive hydrogel/micelle composites constructed with biocompatible materials can be a promising sustained-release or site-specific drug delivery system for instable or hydrophobic drugs.

NGR-modified pH-sensitive liposomes for controlled release and tumor target delivery of docetaxel.

As current tumor chemotherapy faces many challenges, it is important to develop drug delivery systems with increased tumor-targeting ability, enhanced therapeutic effects and reduced side effects. In this study, a pH-sensitive liposome was constructed containing CHEMS-anchored PEG2000 for extended circulation and NGR peptide as the targeting moiety. The NGR-modified docetaxel-loaded pH-sensitive extended-circulation liposomes (DTX/NGR-PLL) prepared possess suitable physiochemical properties, including particle size of approximately 200nm, drug encapsulation efficiency of approximately 70%, and pH-sensitive drug release properties. Experiments performed in vitro and in vivo on human fibrosarcoma cells (HT-1080) and human breast adenocarcinoma cells (MCF-7) verified the specific targeting ability and enhanced antitumor activity to HT-1080 cells. The results of intravenous administration demonstrated that NGR-modified liposomes can significantly and safely accumulate in tumor tissue in xenografted nude mice. In conclusion, the liposomes constructed hold promise as a safe and efficient drug delivery system for specific tumor treatment.

Combination of using prodrug-modified cationic liposome nanocomplexes and a potentiating strategy via targeted co-delivery of gemcitabine and docetaxel for CD44-overexpressed triple negative breast cancer therapy.

In this study, novel prodrug-modified cationic liposome nanocomplexes (Combo NCs) were reported for gemcitabine (GEM) and docetaxel (DTX) co-delivery. This nanoplatform exhibited multiple favorable characteristics, such as a 'green' fabrication with a one-step chemical reaction, appropriate size (∼200nm) and distribution (PDI<0.2), low zeta potential (-31.1mv), high drug-loading efficiency (9.3% GEM plus 3.1% DTX, wt%) and pH and enzymatic dual-stimulus-responsive release properties. Immunofluorescence and cellular uptake studies showed that Combo NCs efficiently targeted overexpressed CD44 in MDA-MB-231 carcinoma. In vitro studies revealed that Combo NCs played a critical role in the synergistic induction of cytotoxicity, apoptosis and inhibition of wound healing. Combo NCs were confirmed to exhibit great potency for increasing S phase arrest and remodeling the CDA and dCK balance by decreasing the mRNA expression of CDA down to 0.09-fold and increasing the mRNA expression of dCK by 1.36-fold, remarkably increasing the dCK/CDA ratio to 15.3-fold compared with the blank control. The biodistribution results obtained in vivo revealed an effective accumulation in tumor foci. All of these advantages of Combo NCs contributed to their remarkable anti-tumor efficacy without systemic toxicity as well as their apoptosis-enhancing and anti-proliferative capacities, as determined by TUNEL and Ki67 immunohistochemistry in vivo. Consequently, such a rationally contemplated co-delivery system demonstrated the promising potential of clinical applications for triple-negative breast cancer therapy. STATE OF SIGNIFICANCE: The Combo NCs were innovatively applied for co-delivery of hydrophilic GEM and hydrophobic DTX. The ester bond linking and shielding effect of HA-GEM made the carriers achieve synchronous release properties, which was determined in in vitro release study. Due to the HA modification, the vectors own great potency for positive targeting to CD44 overexpressed triple-negative breast cancer cells MDA-MB-231. Cytotoxicity and apoptosis studies confirmed the targeting effect and synergism between two drugs. Interestingly, we found in cell cycle study, drug combinations (free combination or Combo NCs) didn't show a rise in G2M phase, which was significantly higher when treated DTX alone. We further discovered the role of DTX in combinations may involve in modulating GEM associated enzymes thus enhancing the efficacy of GEM. Consequently, this nanoplatform provided a novel solution for achieving targeted co-delivery and potentiating effect in cancer therapy.

Lactoferrin conjugated PEG-PLGA nanoparticles for brain delivery: preparation, characterization and efficacy in Parkinson's disease.

A novel biodegradable brain drug delivery system, the lactoferrin (Lf) conjugated polyethylene glycol-polylactide-polyglycolide (PEG-PLGA) nanoparticle (Lf-NP) was constructed in this paper with its in vitro and in vivo delivery properties evaluated by a fluorescent probe coumarin-6. Lf was thiolated and conjugated to the distal maleimide function surrounding on the pegylated nanoparticle to form Lf-NP. TEM observation and ELISA analysis confirmed the existence of active Lf on the surface of Lf-NP. The results of qualitative and quantitative uptake studies of coumarin-6 incorporated Lf-NP showed a more pronounced accumulation of Lf-NP in bEnd.3 cells than that of unconjugated nanoparticle (NP). Further uptake inhibition study indicated that the increased uptake of Lf-NP was via an additional clathrin mediated endocytosis processes. Following intravenous administration, a near 3 fold of coumarin-6 was found in the mice brain carried by Lf-NP compared to that carried by NP. Intravenous injection of urocortin loaded Lf-NP effectively attenuated the striatum lesion caused by 6-hydroxydopamine in rats as indicated by the behavioral test, the immunohistochemistry test and striatal transmitter content detection results. The cell viability test and CD68 immunohistochemistry demonstrated the acceptable toxicity of the system. All these results demonstrated that Lf-NP was a promising brain drug delivery system with reasonable toxicity.