Pian-Pian Chen

Thermo-sensitive hydrogels combined with decellularised matrix deliver bFGF for the functional recovery of rats after a spinal cord injury

Because of the short half-life, either systemic or local administration of bFGF shows significant drawbacks to spinal injury. In this study, an acellular spinal cord scaffold (ASC) was encapsulated in a thermo-sensitive hydrogel to overcome these limitations. The ASC was firstly prepared from the spinal cord of healthy rats and characterized by scanning electronic microscopy and immunohistochemical staining. bFGF could specifically complex with the ASC scaffold via electrostatic or receptor-mediated interactions. The bFGF-ASC complex was further encapsulated into a heparin modified poloxamer (HP) solution to prepare atemperature-sensitive hydrogel (bFGF-ASC-HP). bFGF release from the ASC-HP hydrogel was more slower than that from the bFGF-ASC complex alone. An in vitro cell survival study showed that the bFGF-ASC-HP hydrogel could more effectively promote the proliferation of PC12 cells than a bFGF solution, with an approximate 50% increase in the cell survival rate within 24 h (P < 0.05). Compared with the bFGF solution, bFGF-ASC-HP hydrogel displayed enhanced inhibition of glial scars and obviously improved the functional recovery of the SCI model rat through regeneration of nerve axons and the differentiation of the neural stem cells. In summary, an ASC-HP hydrogel might be a promising carrier to deliver bFGF to an injured spinal cord.

Combination of coenzyme Q10-loaded liposomes with ultrasound targeted microbubbles destruction (UTMD) for early theranostics of diabetic nephropathy

Diabetic nephropathy (DN) is one of the most common and lethal microvascular complications of diabetes. This study aimed to explore whether coenzymeQ10 (CoQ10) as an antioxidant combined with ultrasound-targeted microbubble destruction (UTMD) could reverse the progress of early diabetic nephropathy (DN). CoQ10 has great potential to treat early DN. However, the clinical application of CoQ10 has been limited because of its low aqueous solubility and non-specific distribution. Therefore, CoQ10-loaded liposomes (CoQ10-lip) were prepared and combined with ultrasound microbubbles for the early theranostics of DN. CoQ10-lip exhibited a good round morphology with a diameter of 183±1.7nm and a negative zeta potential of -25.3mV, which was capable of prolonging the release of the encapsulated CoQ10. The early DN rat models were induced by streptozotocin (STZ) and confirmed by contrast-enhanced ultrasound (CEUS) and 24-h urinary albumin. After the administration of CoQ10-lip combined with the UTMD technique to rats with early DN, the morphology and function of the kidney were evaluated by ultrasonography, histological and molecular analyses. The renal hemodynamics were significantly improved, moreover, 24-h urinary protein, and oxidative stress indexes were modulated after treatment with CoQ10-lip+UTMD indicating recovery of renal function. An elevated level of Nphs2 protein and reduced caspase 3 level indicated the preservation of podocytes and inhibition of cell apoptosis after CoQ10-lip+UTMD treatment. The molecular mechanism was associated with the upregulation of Bcl-2 and the downregulation of Bax. Moreover, the combination of CoQ10-lip and ultrasound microbubbles demonstrated a better protective effect on the damaged kidney than the other groups (free CoQ10 or CoQ10-lip+/- UTMD). Conclusively, CoQ10-lip in combination with ultrasound microbubbles might be a potential strategy to reverse the progress of early DN.

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.

Liposomes with Silk Fibroin Hydrogel Core to Stabilize bFGF and Promote the Wound Healing of Mice with Deep Second-Degree Scald

How to maintain the stability of basic fibroblast growth factor (bFGF) in wounds with massive wound fluids is important to accelerate wound healing. Here, a novel liposome with hydrogel core of silk fibroin (SF-LIP) is successfully developed by the common liposomal template, followed by gelation of liquid SF inside vesicle under sonication. SF-LIP is capable of encapsulating bFGF (SF-bFGF-LIP) with high efficiency, having a diameter of 99.8 ± 0.5 nm and zeta potential of -9.41 ± 0.10 mV. SF-LIP effectively improves the stability of bFGF in wound fluids. After 8 h of incubation with wound fluids at 37 °C, more than 50% of free bFGF are degraded, while only 18.6% of the encapsulated bFGF in SF-LIP are destroyed. Even after 3 d of preincubation with wound fluids, the cell proliferation activity and wound healing ability of SF-bFGF-LIP are still preserved but these are severely compromised for the conventional bFGF-liposome (bFGF-LIP). In vivo experiments reveal that SF-bFGF-LIP accelerates the wound closure of mice with deep second-degree scald. Moreover, due to the protective effect and enhanced penetration ability, SF-bFGF-LIP is very helpful to induce regeneration of vascular vessel in comparison with free bFGF or bFGF-LIP. The liposome with SF hydrogel core may be a potential carrier as growth factors for wound healing.

Prevent diabetic cardiomyopathy in diabetic rats by combined therapy of aFGF-loaded nanoparticles and ultrasound-targeted microbubble destruction technique

Acidic fibroblast growth factor (aFGF) has shown the great potential to prevent the structural and functional injuries caused by diabetic cardiomyopathy (DCM). The present study sought to investigate the preclinical performance and mechanism of the combination therapy of aFGF-nanoparticles (aFGF-NP) and ultrasound-targeted microbubble destruction (UTMD) technique for DCM prevention. From Mason staining and TUNEL staining, aFGF-NP+UTMD group showed significant differences from the diabetes group and other groups treated with aFGF or aFGF-NP. The cardiac collagen volume fraction (CVF) and cardiac myocyte apoptosis index in aFGF-NP+UTMD group reduced to 4.15% and 2.31% respectively, compared with those in the diabetes group (20.5% and 11.3% respectively). Myocardial microvascular density (MCD) in aFGF-NP+UTMD group was up to 35n/hpf, much higher than that in the diabetes group (14n/hpf). The diabetes group showed similar results (MCD, CVF and cardiac myocyte apoptosis index) to other aFGF treatment groups (free aFGF±UTMD or aFGF-NP). Indexes from transthoracic echocardiography and hemodynamic evaluation also proved the same conclusion. These results confirmed that the abnormalities including diastolic dysfunctions, myocardial fibrosis and metabolic could be suppressed by the different extents of twice weekly aFGF treatments for 12 consecutive weeks (free aFGF or aFGF-NP±UTMD), with the strongest improvements observed in the aFGF-NP+UTMD group. Western blot and immunohistochemical analyses of heart tissue samples further revealed the high efficiency of heart-targeted delivery and effective cardioprotection with this combination approach. Overall, this study has generated supportive data that are critical for the translation of a promising DCM prevention strategy.

Enhanced neuroprotection with decellularized brain extracellular matrix containing bFGF after intracerebral transplantation in Parkinson’s disease rat model

Extracellular matrix-based biomaterials have many advantages over synthetic polymer materials for regenerative medicine applications. In central nervous system (CNS), basic fibroblast growth factor (bFGF) is widely studied as a potential agent for Parkinsons disease (PD). However, the poor stability of bFGF hampered its clinical use. In this study, CNS-derived biologic scaffold containing bFGF was used to enhance and extend the neuroprotective effect of bFGF on PD targeted therapy. Decellularized brain extracellular matrix (dcBECM) was prepared by chemical extraction. The biocompatibility of dcBECM was evaluated using CCK-8 assay and magnetic resonance imaging (MRI). The controlled-release behavior of dcBECM containing bFGF (bFGF+dcBECM) was confirmed by ELISA assay. Furthermore, the cytocompatibility and neuroprotective effect of bFGF+dcBECM was evaluated in vitro and in vivo. From results, dcBECM showed a three-dimensional network structure with high biocompatibility. MRI of dcBECM implanted rats showed nearly seamless fusion of dcBECM with the adjoining tissues. The cumulative release rate of bFGF+dcBECM in vitro reached to 75.88% at 10h and maintained sustained release trend during the observation. ELISA results in vivo further confirmed the sustained-release behavior (from 12h to 3d) of bFGF+dcBECM in brain tissues. Among the experimental groups, bFGF+dcBECM group showed the highest cell survival rate of PD model cells, improved behavioral recovery and positive expressions of neurotrophic proteins in PD recovered rats. In conclusion, sustained neuroprotection in PD rats was achieved by using bFGF+dcBECM. The combination of dcBECM and bFGF would be a promising therapeutic strategy to realize an effective and safe alternative for CNS disease treatment.

CoQ10-loaded liposomes combined with UTMD prevented early nephropathy of diabetic rats

Nephropathy is one of the most severe complications of diabetic patients. The therapeutic strategies for diabetic patients should not only focus on the control of blood glucose but also pay attention to the occurrence of diabetic nephropathy (DN). Coenzyme Q10 (CoQ10) has great therapeutic potential for DN. However, the clinical application of CoQ10 has been limited because of its low water-solubility and non-specific distribution. Liposomes were supposed to be an effective way for delivering CoQ10 to kidney. CoQ10 was effectively encapsulated into the liposome (CoQ10-LIP) with a high entrapment efficiency of 86.15 %. The CoQ10-LIP exhibited a small hydrodynamic diameter (180 ± 2.1 nm) and negative zeta potential (−18.20 mV). Moreover, CoQ10-LIP was combined with ultrasound-mediated microbubble destruction (UTMD) to enhance specific distribution of CoQ10 in kidney. In early stage of diabetic mellitus (DM), rats were administrated with CoQ10-LIP followed by UTMD (CoQ10-LIP+UTMD) to prevent occurrence of DN. Results revealed that CoQ10-LIP+UTMD effectively prevented the renal morphology and function of diabetics rats from damage. The protective mechanism of CoQ10-LIP was highly associated with protecting podocyte, promoting vascular repair and inhibiting cell apoptosis. Conclusively, CoQ10-LIP in combination with UTMD might be a potential strategy to prevent occurrence of DN.

Silk fibroin nanoparticles dyeing indocyanine green for imaging-guided photo-thermal therapy of glioblastoma

Abstract Silk was easily dyed in traditional textile industry because of its strong affinity to many colorants. Herein, the biocompatible silk fibroin was firstly extracted from Bombyx mori silkworm cocoons. And SF nanoparticles (SFNPs) were prepared for dyeing indocyanine green (ICG) and construct a therapeutic nano-platform (ICG-SFNPs) for photo-thermal therapy of glioblastoma. ICG was easily encapsulated into SFNPs with a very high encapsulation efficiency reaching to 97.7 ± 1.1%. ICG-SFNPs exhibited a spherical morphology with a mean particle size of 209.4 ± 1.4 nm and a negative zeta potential of −31.9 mV, exhibiting a good stability in physiological medium. Moreover, ICG-SFNPs showed a slow release profile of ICG in vitro, and only 24.51 ± 2.27% of the encapsulated ICG was released even at 72 h. Meanwhile, ICG-SFNPs exhibited a more stable photo-thermal effect than free ICG after exposure to near-infrared irradiation. The temperature of ICG-SFNPs rapidly increased by 33.9 °C within 10 min and maintained for a longer time. ICG-SFNPs were also easily internalized with C6 tumor cells in vitro, and a strong red fluorescence of ICG was observed in cytoplasm for cellular imaging. In vivo imaging showed that ICG-SFNPs were effectively accumulated inside tumor site of C6 glioma-bearing Xenograft nude mice through vein injection. Moreover, the temperature of tumor site was rapidly rising up to kill tumor cells after local NIR irradiation. After treatment, its growth was completely suppressed with the relative tumor volume of 0.55 ± 033 while free ICG of 33.72 ± 1.90. Overall, ICG-SFNPs may be an effective therapeutic means for intraoperative phototherapy and imaging.

Skin-permeable liposome improved stability and permeability of bFGF against skin of mice with deep second degree scald to promote hair follicle neogenesis through inhibition of scar formation

Excessive deposition of extracellular matrix (ECM) usually resulted in scar formation during wound healing, which caused skin dysfunction, such as hair loss. Basic fibroblast growth factor (bFGF) was very helpful for promoting hair follicle neogenesis and regulating the remodeling of ECM during wound healing. Because of its poor stability in wound fluids and low permeability against the dense wound scar, the repairing quality of bFGF on wound was hindered largely in clinical practice. To overcome these drawbacks, herein, a novel liposome with silk fibroin hydrogel core (bFGF-SF-LIP) was firstly prepared to stabilize bFGF, followed by insertion of laurocapam, a permeation enhancer, into the liposomal membrane to construct a skin-permeable liposome (SP-bFGF-SF-LIP). The encapsulated efficiency of bFGF was reaching to nearly 90% when ratio of drug/lipids above 1:300, and it activity was not compromised by laurocapam. SP-bFGF-SF-LIP exhibited a hydrodynamic diameter of 103.3 nm and Zeta potential of -2.31 mV. The stability of the encapsulated bFGF in wound fluid was obviously enhanced. After 24 h of incubation with wound fluid containing MMP-9, the remaining bFGF was as high as 65.4 ± 0.5% for SP-bFGF-SF-LIP, while only 2.1 ± 0.2% of free bFGF was remained. The skin-permeability of bFGF was significantly enhanced by SP-bFGF-SF-LIP and most of the encapsulated bFGF penetrated into the dermis. After treatment with SP-bFGF-SF-LIP, the morphology of hair follicle at wound zone was obviously improved and the hair regrew on the deep second scald mice model. The therapeutic mechanism was highly associated with inhibiting scar formation and promoting vascular growth in dermis. Conclusively, SP-bFGF-SF-LIP may a potential option to improve wound healing with high-quality.