Using PG-Liposome-Based System to Enhance Puerarin Liver-Targeted Therapy for Alcohol-Induced Liver Disease.

A critical issue for alcohol-induced liver disease (ALD) therapeutics is the lack of a highly efficient delivery system. In this study, a Puerarin-propylene glycol-liposome system was prepared for the purpose of targeting puerarin, an isoflavon, to the liver. Transmission electron microscope (TEM) results showed the liposomes to be spherical in shape with an average diameter of 182 nm with a polydispersity index of 0.239. The zeta potential of the particles was about -30 mV. The entrapment efficiency of puerarin was above 90%. MTT-based assay in HpeG2 cells showed no significant cytotoxicity in the presence of up to 25% concentration of the system containing 3% puerarin. In vivo performance of this system was studied in mice. Pharmacokinetics and distribution of puerarin-PG-liposome system was studied relative to puerarin solution at the same dose levels. The results show that puerarin-PG-liposome prolonged drug retention time and decreased elimination of puerarin in mice (AUC of liposome system and solution was 9.5 and 4.0 mg h L-1, respectively). Furthermore, propylene glycol (PG)-liposome system enhanced puerarin distribution into liver and spleen, while decreasing puerarin distribution in other tissues. Overall, the puerarin-PG-liposome system showed enhanced therapeutic effect in mice with ALD.

Skin-penetrating polymeric nanoparticles incorporated in silk fibroin hydrogel for topical delivery of curcumin to improve its therapeutic effect on psoriasis mouse model.

A poor percutaneous penetration capability for most topical anti-inflammatory drugs is one of the main causes compromising their therapeutic effects on psoriatic skin. Even though curcumin has shown a remarkable efficacy in the treatment of psoriasis, its effective penetration through the stratum corneum is still a major challenge during transdermal delivery. The aim of our study was to design skin-permeating nanoparticles (NPs) to facilitate delivery of curcumin to the deeper layers of the skin. A novel amphiphilic polymer, RRR-α-tocopheryl succinate-grafted-ε-polylysine conjugate (VES-g-ε-PLL) was synthesized and self-assembled into polymeric nanoparticles. The nanoparticles of VES-g-ε-PLL exhibiting an ultra-small hydrodynamic diameter (24.4nm) and a positive Zeta potential (19.6mV) provided a strong skin-penetrating ability in vivo. Moreover, curcumin could effectively be encapsulated in the polymeric nanoparticles with a drug loading capacity of 3.49% and an encapsulating efficiency of 78.45%. In order to prolong the retention time of the ultra-small curcumin-loaded nanoparticles (CUR-NPs) in the skin, silk fibroin was used as a hydrogel-based matrix to further facilitate topical delivery of the model drug. In vitro studies showed that CUR-NPs incorporated in silk fibroin hydrogel (CUR-NPs-gel) exhibited a slower release profile of curcumin than the plain CUR-gel, without compromising the skin penetration ability of CUR-NPs. In vivo studies on miquimod-induced psoriatic mice showed that CUR-NPs-gel exhibited a higher therapeutic effect than CUR-NPs as the former demonstrated a more powerful skin-permeating capability and a more effective anti-keratinization process. CUR-NPs-gel was therefore able to inhibit the expression of inflammatory cytokines (TNF-α, NF-κB and IL-6) to a greater extent. In conclusion, the permeable nanoparticle-gel system may be a potential carrier for the topical delivery of lipophilic anti-psoriatic drugs.

Using NGF heparin-poloxamer thermosensitive hydrogels to enhance the nerve regeneration for spinal cord injury.

OBJECTIVE: Nerve growth factor (NGF) has potential in spinal cord injury (SCI) therapy, but limited by the poor physicochemical stability and low ability to cross the blood spinal cord barrier. Novel heparin-poloxamer (HP) thermo-sensitive hydrogel was constructed to enhance the NGF regeneration on SCI. METHOD: NGF-HP thermo-sensitive hydrogel was prepared and related characteristics including gelation temperature, rheological behavior and micromorphology were measured. Local NGF delivery to the injured spinal cord was achieved by in situ injection in the injured space. The cellular uptake of NGF-HP hydrogel was evaluated with PC12 cells in vitro. Pathologic characteristics and neuron regeneration effects on the SCI rats were studied to evaluate the enhanced therapy of NGF-HP hydrogel. Endoplasmic reticulum (ER) stress-induced apoptosis was analyzed to explore the related mechanism in SCI regeneration. RESULTS: NGF-HP hydrogel showed good morphology and stable bioactivity of NGF in vitro. NGF-HP hydrogel combined treatment significantly enhanced the efficiency of NGF cellular uptake (P<0.05) without obvious cytotoxicity. Significant improvements in both neuron functions and tissue morphology on the SCI rats were observed in NGF-HP hydrogel group. Compared with free HP hydrogel and NGF treatment groups, NGF-HP hydrogel group showed significant inhibition on the formation of glial scars in the extreme crushed rat SCI model. The neuroprotective effects of NGF-HP were related to the inhibition of chronic ER stress-induced apoptosis. CONCLUSIONS: HP hydrogel combined with orthotopic injection technique might be an effective method to deliver NGF into the injured site, which will provide an effective strategy for SCI regeneration. STATEMENT OF SIGNIFICANCE: Spinal cord injury (SCI) is a devastating condition that can lead to sudden loss of sensory and autonomic function. Current treatment includes decompression surgery, injury stabilization, secondary complications prevention and rehabilitation. However, neurological recovery is limited. Nerve growth factor (NGF) has potential in SCI therapy, but limited by the poor physicochemical stability and low ability to cross the blood spinal cord barrier. Hydrogels have good affinity and compatibility to biological tissue. In this study, we developed a novel heparin-poloxamer (HP) thermo-sensitive hydrogel to enhance the spinal cord regeneration of NGF. From SCI rat experiment, HP hydrogel combined with orthotopic injection technique showed best neuroprotective effects among experimental groups. This novel combined technique will provide an effective strategy for SCI regeneration.

Intranasal delivery of bFGF with nanoliposomes enhances in vivo neuroprotection and neural injury recovery in a rodent stroke model.

Basic fibroblast growth factor (bFGF) may protect stroke patients from cerebral ischemia-reperfusion (I/R) injury. In this study, we report the intranasal use of novel nanoliposomes for the brain delivery of bFGF in a rat model of cerebral I/R. Compared with free bFGF, nanoliposomal therapy was able to significantly improve bFGF accumulation in brain tissues (p<0.05) including the most affected ischemic penumbra regions (e.g. hippocampus, pallium). After intranasal bFGF-nanoliposomal treatment for 3 consecutive days, functional recovery as indicated by improved neurologic deficit score and spontaneous locomotor activity was observed, and the stroke infarct volume was nearly halved (p<0.001) which persisted after 21days. These neuroprotective effects could be blocked by the PI3-K/Akt inhibitor LY294002, indicating the involvement of PI3-K/Akt activation in the therapeutic action. Overall, our results support the intranasal use of nanoliposomal bFGF as an efficient, non-invasive means to bypass the blood-brain barrier for ischemic stroke treatment.

Glioma-targeted therapy using Cilengitide nanoparticles combined with UTMD enhanced delivery.

Malignant gliomas especially glioblastoma (GBM) are poorly responsive to the current treatments. Cilengitide (CGT) is a cyclic pentapeptide that demonstrated efficacy for GBM treatment by targeting the integrins avß3 and avß5 over-expressed on GBM cells. However, clinical translation of this therapy has been limited by issues including fast blood clearance, high kidney and liver uptake, poor blood-brain barrier (BBB) penetration, low tumor specificity and rapid washout from tumors. In this study, these issues were tackled in an integrated manner using a multi-stage strategy combining ultrasound-targeted microbubble destruction (UTMD) with CGT nanotherapy. CGT nanoparticles (CGT-NP) prepared using gelatin and Poloxamer 188-grafted heparin copolymer demonstrated significant apoptotic and cytotoxic effects in C6 GBM cells. Biodistribution study in a rat GBM model demonstrated buildup of high CGT level in tumors subjected to CGT-NP+UTMD combined therapy. The tumor CGT level in these animals was increased over 3-fold, tumor retention of CGT prolonged and renal clearance significantly reduced when compared with free CGT with or without UTMD. CGT-NP+UTMD treatment was further shown to extend the median survival period from less than 20days in the control and about 30days in free CGT group to about 80days. This was achieved with low CGT dosing level (2mg/kg twice weekly). In situ monitoring of GFAP, Ki67, caspase-3, Beclin-1, and LC-3 in the tumor samples together with TUNEL assay, transmission electron microscope imaging and Western blot assay all demonstrated high apoptotic and autophagy activities induced by the combined therapy. In conclusion, this study has provided extensive preclinical data supporting the use of this combined therapy to overcome the limitations of standard CGT treatment of gliomas.

Brain tumor-targeted delivery and therapy by focused ultrasound introduced doxorubicin-loaded cationic liposomes.

Brain tumor lacks effective delivery system for treatment. Focused ultrasound (FUS) can reversibly open BBB without impacts on normal tissues. As a potential drug carrier, cationic liposomes (CLs) have the ability to passively accumulate in tumor tissues for their positive charge. In this study, FUS introduced doxorubicin-loaded cationic liposomes (DOX-CLs) were applied to improve the efficiency of glioma-targeted delivery. Doxorubicin-loaded CLs (DOX-CLs) and quantum dot-loaded cationic liposomes (QD-CLs) were prepared using extrusion technology, and their characterizations were evaluated. With the advantage of QDs in tracing images, the glioma-targeted accumulation of FUS + CLs was evaluated by fluorescence imaging and flow cytometer. Cell survival rate, tumor volume, animal survival time, and brain histology in C6 glioma model were investigated to evaluate the glioma-targeted delivery of FUS + DOX-CLs. DOX-CLs and QD-CLs had suitable nanoscale sizes and high entrapment efficiency. The combined strategy of FUS introduced CLs significantly increased the glioma-targeted accumulation for load drugs. FUS + DOX-CLs showed the strongest inhibition on glioma based on glioma cell in vitro and glioma model in vivo experiments. From MRI and histological analysis, FUS + DOX-CLs group strongly suppressed the glioma progression and extended the animal survival time to 81.2 days. Among all the DOX treatment groups, FUS + DOX-CLs group showed the best cell viability and highest level of tumor apoptosis and necrosis. Combining the advantages of BBB reversible opening by FUS and glioma-targeted binding by CLs, ultrasound introduced cationic liposomes could achieve glioma-targeted delivery, which might be developed as a potential strategy for future brain tumor therapy.