Conductive Polyaniline Patterns on Electrospun Polycaprolactone/Hydroxyapatite Scaffolds for Bone Tissue Engineering

Currently, the challenge for bone tissue engineering is to design a scaffold that would mimic the structure and biological functions of the extracellular matrix and would be able to direct the appropriate response of cells through electrochemical signals, thus stimulate faster bone formation. The purpose of the presented research was to perform and evaluate PCL/n-HAp scaffolds locally modified with a conductive polymer-polyaniline. The material was obtained using electrospinning, and a simple ink-jet printing method was applied to receive the conductive polyaniline patterns on the surface of the electrospun materials. The samples of scaffolds were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal analysis (DSC, TGA), and infrared spectroscopy (FTIR) before and after immersion of the material in Simulated Body Fluid. The effect of PANI patterns on changes in the SBF mineralization process and cell morphology was evaluated in order to prove that the presented material enables the growth and proliferation of bone cells.     

Laponite®: A key nanoplatform for biomedical applications?

Laponite® is a synthetic smectite clay that already has many important technological applications, which go beyond the conventional uses of clays in pharmaceutics and cosmetics. In biomedical applications, particularly in nanomedicine, this material holds great potential. Laponite® is a 2-dimensional (2D) nanomaterial composed of disk-shaped nanoscale crystals that have a high aspect ratio. These disks can strongly interact with many types of chemical entities (from small molecules or ions, to natural or synthetic polymers, to different inorganic nanoparticles) and are also easily functionalized and readily degraded in the physiological environment giving rise to non-toxic and even bioactive products. This review will highlight the potential of Laponite® as a nanomaterial in the fields of drug delivery, bioimaging, tissue engineering and regenerative medicine. New concepts, as well as novel innovative materials that stand out from the usual ones due to the unique properties of Laponite®, will also be presented and discussed.     

Dual sustained release delivery system for multiple route therapy of an antiviral drug

Abstract

Context: The first successful molecule against herpes infections was Acyclovir, which competes with new generations in the market, with its potential activity. The major physicochemical constraints and pharmacokinetics of Acyclovir such as low solubility, poor permeability, less half-life, high dose has initiated many researchers to develop diverse modified release dosage forms.

Objective: The objective of this work was to design polymeric nanoparticles of Acyclovir and then incorporate the drug-loaded nanoparticles within an in situ gelling system to provide dual sustained release effect, whereby the duration of action and bioavailability through different routes of administration could be improved.

Materials and methods: The formulation was designed through 3² factorial design, first developing the nanoparticles using Polycaprolactone and Pluronic F127 by Solvent evaporation process, followed by dispersion of the suspended nanoparticles into thermosensitive in situ gelling system of Pluronic F127 with Carbopol.

Results and discussion: The characterization of the nanoparticles and its sol-gel system performed through zeta sizer, SEM, XRD, TG-DSC, FTIR and rheology helped to optimize the formulation. The drug release could be sustained to 60% and 30% at eight hours, for the nanoparticles and their in situ gel systems, respectively, with non-Fickian diffusion mechanism of drug release. The test for % cell viability with NIH3T3 cell line revealed low level of toxicity for the nanoparticles.

Conclusion: The statistical significance obtained for the trail formulations experimentally proved its suitability for this dosage form design to achieve desired level of drug release.     

Neocollagenesis in human tissue injected with a polycaprolactone-based dermal filler

A novel dermal filler containing polycaprolactone (PCL) has been introduced into the aesthetic market. A recently published study has shown that the PCL-based dermal filler induces neocollagenesis, a process associated with improvement in appearance of the skin, in rabbit tissue. In this pilot study, we investigated whether the PCL-based dermal filler induces neocollagenesis in human tissue by histological analysis. Two patients who were enrolled in the study, and were willing to undergo temple lifting surgery, were injected intra-dermally with the PCL-based dermal filler. Thirteen months post-injection, biopsies were obtained for subsequent histological analysis. Histological analysis of tissue obtained from the biopsies (13 months post-injection) revealed that the PCL-based dermal filler shows collagen formation around the PCL particles and, therefore, supports similar findings previously shown in rabbit tissue. In conclusion, PCL particles are maintained in their original state 13 months post-injection.     

Eugenol nanocapsule for enhanced therapeutic activity against periodontal infections

Eugenol is a godsend to dental care due to its analgesic, local anesthetic, and anti-inflammatory and antibacterial effects. The aim of the present research work was to prepare, characterize and evaluate eugenol-loaded nanocapsules (NCs) against periodontal infections. Eugenol-loaded polycaprolactone (PCL) NCs were prepared by solvent displacement method. The nanometric size of the prepared NCs was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The in vitro drug release was found to follow a biphasic pattern and followed Michaelis–Menten like model. The percentage cell viability values near to 100 in the cell viability assay indicated that the NCs are not cytotoxic. In the in vivo studies, the eugenol NC group displayed significant difference in the continuity of epithelium of the interdental papilla in comparison to the untreated, pure eugenol and placebo groups. The in vivo performance of the eugenol-loaded NCs using ligature-induced periodontitis model in rats indicated that eugenol-loaded NCs could prevent septal bone resorption in periodontitis. On the basis of our research findings it could be concluded that eugenol-loaded PCL NCs could serve as a novel colloidal drug delivery system for enhanced therapeutic activity of eugenol in the treatment of periodontal infections.     

Development and evaluation of carboplatin-loaded PCL nanoparticles for intranasal delivery

Context: The study was aimed to develop a polymeric nanoparticle formulation of anticancer drug carboplatin using biodegradable polymer polycaprolactone (PCL). The formulation is intended for intranasal administration to treat glioma anticipating improved brain delivery as nasal route possess direct access to brain and nanoparticles have small size to overcome the mucosal and blood–brain barrier.

Objective: Development and evaluation of carboplatin-PCL nanoparticles for brain delivery by nasal route.

Methodology: Carboplatin-loaded PCL nanoparticles (CPCs) were prepared by double emulsion-solvent evaporation technique and characterized by particle size, zeta potential, entrapment efficiency, scanning electron microscopy and differential scanning calorimetry. The CPCs were assessed for in vitro release kinetics, ex vivo permeation and in situ nasal perfusion. Cytotoxic potential of CPCs in vitro was evaluated on LN229 human glioblastoma cells.

Results and discussion: The optimized formulation of carboplatin-PCL nanoparticle CPC-08 with particle size of 311.6?±?4.7?nm and zeta potential ?16.3?±?3.7?mV exhibited percentage entrapment efficiency of 27.95?±?4.21. In vitro drug release showed initial burst release followed by slow and continues release indicating biphasic pattern. The ex vivo permeation pattern through sheep nasal mucosa also exhibited a similar release pattern as for in vitro release studies. In situ nasal perfusion studies in Wistar rats demonstrate that CPCs show better nasal absorption than carboplatin solution. In vitro cytotoxicity studies on LN229 cells showed an enhancement in cytotoxicity by CPCs compared to carboplatin alone.

Conclusion: CPC-08 effectively improves nasal absorption of carboplatin and can be used for intranasal administration of carboplatin for improved brain delivery.     

甲壳素-聚己内酯复合接骨板的生物吸收率研究

目的 :了解甲壳素 聚己内酯复合可吸收接骨板在动物体内的降解速度及随时间的变化。　方法 :在实验组中 ,将甲壳素 聚己内酯复合可吸收接骨板及螺钉 ,包埋于 2 8只新西兰白兔右胫骨中段 ;在对照组中 ,选择 8只新西兰白兔 ,于相应部位植入金属钢板。实验组动物于手术后 2、4、6、8、12、2 4、36周处死。对照组于术后 4、8周时分别处死。实验组的动物均行生物吸收率 (BAR)测定。　结果 :甲壳素 聚己内酯复合接骨板及螺钉在动物体内可降解。 4周组吸收率为 4 .36 % ,6周组为 7.13% ,12周组为 12 .8% ,36周组为 16 .37%。　结论 :甲壳素 聚己内酯复合接骨板在体内可吸收 ,随时间的延长 ,生物吸收率逐渐增加 ,但不成线性关系     

可降解聚己内酯的体外生物学安全性评价

目的：评价可降解聚己内酯的体外生物学安全性。方法：采用可降解PCL的浸出液进行了急性毒性试验，Ames试验、微核试验、肌肉刺激实验、热源试验。结果：PCL浸出液对小鼠的生长及细胞无毒性作用，Ames试验及微核试验结果证明PCL对细胞染色体、DNA水平的遗传物质无损害作用，热源试验及肌肉刺激试验结果证明PCL无免疫原性。结论：CL是一个具有良好的生物相容性、无毒性、无免疫原性的材料。     

Biomimetic carbon nanotubes for neurological disease therapeutics as inherent medication

Nowadays, nanotechnology is revolutionizing the approaches to different fields from manufacture to health. Carbon nanotubes (CNTs) as promising candidates in nanomedicine have great potentials in developing novel entities for central nervous system pathologies, due to their excellent physicochemical properties and ability to interface with neurons and neuronal circuits. However, most of the studies mainly focused on the drug delivery and bioimaging applications of CNTs, while neglect their application prospects as therapeutic drugs themselves. At present, the relevant reviews are not available yet. Herein we summarized the latest advances on the biomedical and therapeutic applications of CNTs in vitro and in vivo for neurological diseases treatments as inherent therapeutic drugs. The biological mechanisms of CNTs-mediated bio-medical effects and potential toxicity of CNTs were also intensely discussed. It is expected that CNTs will exploit further neurological applications on disease therapy in the near future.