Biodegradable Polymer Polycaprolactone Research Articles

Ambient-dried, scalable and biodegradable cellulose nanofibers aerogel for oil-spill cleanup

Aerogels made of surface-modified cellulose nanofibers (CNF) have the potential to be a long-term solution for oil spill cleanup and industrial waste-water treatment, but their use is currently constrained by high preparation costs, lengthy processing times, and use of hazardous chemicals. In this study, a cost-effective and easily scalable cellulose nanofibers aerogel is developed using sugarcane bagasse as the cellulose source. The aqueous suspension of CNF and urea is freeze-thawed and then dried at ambient temperatures to produce CNF aerogels, avoiding the costly and time-consuming freeze-drying or supercritical drying methods. The role of urea in the aerogel structure is investigated using molecular dynamics. The aerogel exhibited an elastic modulus of 1345 KPa and a porosity of 96.9 %. To enhance the hydrophobicity of the surface of these aerogels, they are coated with the biodegradable polymer polycaprolactone (PCL). Further, two molecular weights (MW) PCL 10,000 and 80,000 are used to examine the impact of PCL MW on the performance and biodegradability of aerogel. Moreover, the efficacy of these green modifications is being compared to the conventional silane modifications. The 10,000 MW PCL-modified aerogel demonstrated a water-contact angle measuring 125.5°, an oil sorption capacity of 24 g/g, and exceptional recyclability even after undergoing 20 cycles. Further, after 15 days, the aerogel showed excellent biodegradability.

Nanographene-Au fine-tuning to intensify plasmonic-resonance of polymeric hybrid bionanosystem for synergistic phototherapy and nerve photobiomodulation

Here, we report the multi-photo-bioactivity of the plasmonic-nano graphitic coordinated polycaprolactone-based aligned nanofibrous scaffolds-based bionanosystem for photothermal breast and colon cancer therapies and peripheral nerve photobiomodulation. The size-optimized colloidal reduced graphene oxide (nRGO, 180 nm) nanosheets, for enhanced photothermal impact, were surface-functionalized with gold nanospheres (AuNPs) to prepare the nRGO@AuNP monodispersed nano-composite and then doped 2.0 mg of nRGO@AuNP in biocompatible and biodegradable polymer polycaprolactone (PCL) to fabricate the nRGO@AuNP-PCL (2.0 mg) plasmonic aligned nanofibrous scaffolds. More than 90% of cancer cells, breast cancer (MCF-7) as well as colon cancer (CT-26), ablated after 5 min of low NIR (808 nm) laser power (0.72 W/cm2) illumination with nRGO@AuNP-PCL (2.0 mg) aligned nanofibrous scaffolds. Besides, the nRGO@AuNP-PCL (2.0 mg) provided an extraordinary microenvironment for adhesion, nerve growth, proliferation, and differentiation of PC12 and S42 cells which mimics the natural extracellular matrix. The 2.5-fold increase in neurite length was observed with NIR illumination after 3 days whereas 1.7-fold was found without NIR illumination after 7 days in comparison to PCL (pure). The current findings will be useful to provide a new crucial approach for preparing biocompatible multifunctional composite plasmonic nanofibers as a highly efficient distinct platform for photothermal therapies and promising bioimplants to overcome the loss of sensation after cancer surgery through nerve photobiomodulation.

Inhalable spray-dried polycaprolactone-based microparticles of Sorafenib Tosylate with promising efficacy on A549 cells

The study developed and evaluated Sorafenib Tosylate (SRT)-loaded polymeric microparticles (MPs) using biodegradable polymer polycaprolactone (PCL) as a potential inhalable carrier for NSCLC. MPs were prepared by spray-drying an oil-in-water (o/w) emulsion. The optimized MPs demonstrated excellent flowability, particle size of 2.84 ± 0.5 μm, zeta potential of −14.0 ± 1.5 mV, and 85.08 ± 5.43% entrapment efficiency. ATR-FTIR/DSC studies revealed a lack of characteristic peaks of the crystalline drug signifying good entrapment of the drug. MPs were spherical and uniform in SEM pictures. The MPs showed a biphasic release pattern up to 72h. The Anderson cascade impactor (ACI) investigation demonstrated the highest drug deposition at stage 4, which revealed that the MPs can reach the lungs’ secondary and terminal bronchi. Inhalable MPs had an efficient aerodynamic property with a mass median aerodynamic diameter (MMAD) of 2.63 ± 1.3 μm, a geometric standard deviation (GSD) of 1.93 ± 0.2 μm, and a fine particle fraction (FPF) of 87 ± 2.5%. Finally, in cytotoxicity studies on A549 cancer cells, MPs had an IC50 value of 0.6011 ± 0.8 μM, which was 85.68% lower than free drug. These findings suggest SRT-loaded inhalable PCL-based MPs as a novel NSCLC treatment.

Workflow for Fabricating 3D-Printed Resorbable Personalized Porous Scaffolds for Orofacial Bone Regeneration.

Resorption of alveolar bone following tooth extraction is a physiological process that can oftenprevent the placement of dental implants due to the limited bone remaining. In severe cases, vertical bone augmentation, which aims to restore bone in an extraskeletal dimension (outside of the skeletal envelope), is required prior to implant placement. While current treatment strategies rely on autologous grafts, or "Guided Bone Regeneration" involving the placement of particulate bone grafting biomaterials under a protective membrane, the field is shifting to patient-matched solutions. Herein, we describe the various steps required for modeling the patient data, creating the patient-matched scaffold geometry and 3D-printing using the biodegradable polymer polycaprolactone for application in the oro-dental and craniofacial areas.

High‐performance sodium ion conducting gel polymer electrolyte based on a biodegradable polymer polycaprolactone

AbstractGel polymer electrolytes (GPEs) are gaining recent focus for high‐performance quasi‐solid‐state energy storage devices owing to their high ionic conductivity, good interfacial properties, flexibility with high safety in comparison to liquid electrolytes. Among various polymer hosts, developed so far, polycaprolactone (PCL) is attractive for its biodegradable and biocompatible nature. In this report, we demonstrate a novel GPE composition incorporating a liquid electrolyte 1 M sodium triflurosulfonate (NaTf) in ethylene carbonate (EC):propylene carbonate (PC) mixture, immobilized in PCL as the host polymer in the form of mechanically stable, free‐standing and flexible thick films. The GPE films are characterized using various physicochemical and electrochemical techniques. The GPE comprising an approximately 80 wt.% concentration of liquid electrolyte offers an optimum ionic conductivity of ~1.3 × 10−3 S cm−1, wide electrochemical stability window up to approximately 4.3 V and high sodium ion transport number (tNa+ ~ 0.67) at room temperature. Besides, the GPE film is thermally stable up to approximately 100°C. The sodium stripping/plating tests reveal highly stable cycling under ±46 mV for over 100 hours followed by ±30 mV at a current density of 0.05 mA cm−2 indicating reversible Na‐plating/stripping behavior. The high Na+‐conductivity and suitable Na‐storage properties make a favorable biodegradable electrolyte for practical sodium‐ion battery applications.

Enzyme cascade converting cyclohexanol into ε-caprolactone coupled with NADPH recycling using surface displayed alcohol dehydrogenase and cyclohexanone monooxygenase on E. coli.

SummaryThe application of enzymes as biocatalysts in industrial processes has great potential due to their outstanding stereo‐, regio‐ and chemoselectivity. Using autodisplay, enzymes can be immobilized on the cell surface of Gram‐negative bacteria such as Escherichia coli. In the present study, the surface display of an alcohol dehydrogenase (ADH) and a cyclohexanone monooxygenase (CHMO) on E. coli was investigated. Displaying these enzymes on the surface of E. coli resulted in whole‐cell biocatalysts accessible for substrates without further purification. An apparent maximal reaction velocity V MAX(app) for the oxidation of cyclohexanol with the ADH whole‐cell biocatalysts was determined as 59.9 mU ml−1. For the oxidation of cyclohexanone with the CHMO whole‐cell biocatalysts a V MAX(app) of 491 mU ml−1 was obtained. A direct conversion of cyclohexanol to ε‐caprolactone, which is a known building block for the valuable biodegradable polymer polycaprolactone, was possible by combining the two whole‐cell biocatalysts. Gas chromatography was applied to quantify the yield of ε‐caprolactone. 1.12 mM ε‐caprolactone was produced using ADH and CHMO displaying whole‐cell biocatalysts in a ratio of 1:5 after 4 h in a cell suspension of OD578nm 10. Furthermore, the reaction cascade as applied provided a self‐sufficient regeneration of NADPH for CHMO by the ADH whole‐cell biocatalyst.

Energy harvesting with flexible piezocomposite fabricated from a biodegradable polymer

Technological advancement is generating a heap of electronic waste and has put onus on the production of wearable electronic systems to be environmentally sustainable without compromising much with their functionality. Many such systems employ flexible piezo sensors for force sensing and/or energy harvesting. In this work, we demonstrate the feasibility of fabricating a flexible piezoelectric energy harvester and sensor by reinforcing a biodegradable polymer polycaprolactone (PCL) with powders of ferroelectric-based piezoceramic systems PbTiO3–Bi(Zr0.5Ni0.5)O3 (PT-BNZ) and 1. The output volume power density of PCL-PTBNZ and PCL-BST was found to be 98.5 and 17 μW/cm3, respectively, for solenoid plunger pressure impact. The corresponding values in the tapping mode are 2556 and 1505 μW/cm3, respectively. The power output derived is significant and can be used to power micro and nano size electronic devices. Such composites can provide a better environment friendly and sustainable alternative to the current piezo energy harvesters.

Thermoresponsive Poly (N‐Isopropylacrylamide)/Polycaprolacton Nanofibrous Scaffolds for Controlled Release of Antibiotics

Smart antibacterial materials capable of releasing antibiotic drugs upon exposure to external triggers are highly desired for various medical applications. Herein, the fabrication of thermosensitive drug‐loaded core−shell nanofibers using the electrospinning technique combined with in situ UV photopolymerization is reported on. The electrospinning method is used for shaping the core structure comprising biodegradable polymer polycaprolactone (PCL). The PCL fibers are coated with the temperature‐responsive poly‐N‐isopropylacrylamide (PNIPAM) via a UV photopolymerization process that allows to precisely control the shell thickness as verified by transmission electron microscope (TEM) analysis. The temperature‐dependent switchable wettability of prepared core−shell fibers is investigated and visualized though water contact angle measurements below and above the lower critical solution temperature. Loading of the antibiotic drug doxycycline hyclate (Doxy) in the PCL core nanofibers results in drug‐encapsulating fiber meshes that allow diffusion of drug molecules through the PNIPAM shell in a temperature‐dependent manner. The antibacterial activity is examined using Gram‐negative Escherichia coli (E. coli) as well as Gram‐positive Staphylococcus aureus (S. aureus) bacteria. The results demonstrate the high suitability of prepared biocompatible electrospun core−shell PCL/PNIPAM nanofibers as carriers for antibiotic drugs with temperature‐sensitive release behavior.

Conversion of Cyclohexane to 6-Hydroxyhexanoic Acid Using Recombinant Pseudomonas taiwanensis in a Stirred-Tank Bioreactor

6-hydroxyhexanoic acid (6HA) represents a polymer building block for the biodegradable polymer polycaprolactone. Alternatively to energy- and emission-intensive multistep chemical synthesis, it can be synthesized directly from cyclohexane in one step by recombinant Pseudomonas taiwanensis harboring a 4-step enzymatic cascade without the accumulation of any intermediate. In the present work, we performed a physiological characterization of this strain in different growth media and evaluated the resulting whole-cell activities. RB and M9* media led to reduced gluconate accumulation from glucose compared to M9 medium and allowed specific activities up to 37.5 ± 0.4 U gCDW−1 for 6HA synthesis. However, 50% of the specific activity was lost within 1 h in metabolically active resting cells, specifying growing cells, or induced resting cells as favored options for long-term biotransformation. Furthermore, the whole-cell biocatalyst was evaluated in a stirred-tank bioreactor setup with a continuous cyclohexane supply via the gas phase. At cyclohexane feed rates of 0.276 and 1.626 mmol min−1 L−1, whole-cell biotransformation occurred at first-order and zero-order rates, respectively. A final 6HA concentration of 25 mM (3.3 g L−1) and a specific product yield of 0.4 g gCDW−1 were achieved with the higher feed rate. Product inhibition and substrate toxification were identified as critical factors limiting biocatalytic performance. Future research efforts on these factors and the precise adjustment of the cyclohexane feed combined with an in situ product removal strategy are discussed as promising strategies to enhance biocatalyst durability and product titer and thus to enable the development of a sustainable multistep whole-cell process.

Evaluation of in-vitro drug release of polyvinylcyclohexane carbonate as a CO2-derived degradable polymer blended with PLA and PCL as drug carriers

Drug delivery via polymers provides advantages such as controlled release over time and constant release rate. Polyvinylcyclohexane carbonate (PVCHC) is a new CO2-derived biodegradable polymer with potential biomedical applications. In this study, biodegradable polymers polycaprolactone (PCL), polylactic acid (PLA), and for the first time, PVCHC, as well as the mixed polymeric matrix of PCL-PVCHC and PLA-PVCHC, were tested as carriers for hydrophilic drugs acetaminophen and clindamycin. The polymeric carriers were prepared as matrix systems by dispersing the polymer powder in acetone solvent and finally by evaporating the matrix's solvent. Thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and FT-IR spectroscopy techniques were employed to characterize the properties of the polymeric drug-carrier matrices. In vitro drug release profiles of acetaminophen and clindamycin in saline phosphate buffer (PBS) and at a temperature of 37 °C were analyzed by UV–Vis spectroscopic technique. The release percentage was calculated at specific time intervals over 24 h. The highest release efficiency for PCL-acetaminophen, PCL-PVCHC-acetaminophen, PLA-acetaminophen, PCL-clindamycin, PLA-clindamycin, and PLA-PVCHC-clindamycin was calculated as 38%, 29%, 39%, 96%, 95%, and 40%, respectively. The kinetic behavior of the drug release was investigated by fitting the release data to the Zero-order model, First-order model, Higuchi model, and Korsmeyer-Peppas model, among which the Korsmeyer-Peppas model had the best agreement with the drug release results.

Electrical Properties Study of Solid Polymer Electrolyte based on PolyCaproLactone/LiCF3SO3 Added Plasticizer

The electrical properties of solid polymer electrolyte based on biodegradable polymer PolyCaproLactone (PCL)/LiCF3SO3 with PC plasticizer addition have been studied. Polymer electrolyte membranes were prepared by solution casting technique by varying propylene carbonate (PC) composition (0-60) % weight. The membranes were characterized by the Electrical Impedance Spectroscopy at room temperature to measure its ionic conductivity and other electrical properties such as dielectric constant and tangent loss. The PCL/LiCF3SO3 system containing 20% weight PC plasticizer exhibits the highest conductivity of 4.92 x 10−4 S/cm at room temperature. The dielectric constant shows decreases with frequency increasing and it depends on dissociation of ions in the polymer electrolyte system. The tangent loss suggests that there are relaxing dipoles in the polymer electrolyte that shift toward higher frequency region. The membrane microstructure also investigated by XRD and the result showed that the PC plasticizer made the PCL/LiCF3SO3 system become more amorphous

Abstract P3-02-11: Topographical ues overlaid with fructose-like molecules to assess breast cancer recruitment in nanofiber scaffolds

Abstract Tumorigenesis is a complex process involving numerous cellular signaling cascades and environmental factors. While 2D cultures for stiffness measurements and more recently 3D cultures to demonstrate differences in cell structures have been reported, very little is known about the impact of sugars in cell recruitment. In this study, we report the fabrication of 3D-scaffolds with different morphologies obtained by electrospinning with fluorescent fructose-like molecular probes to study cancer cell proliferation and migration. Using a FDA approved, biocompatible and biodegradable polymer Polycaprolactone (PCL), we electrospun nanofiber scaffolds having random, aligned, and honeycomb morphologies. Scaffolds with similar morphology without the fructose mimicking analogs were fabricated and used as controls. The degradation rate of the scaffolds was also characterized to ensure long-term availability of probes and mechanical stability of PCL. Cell viability, cell morphology, formation of colonies with changes in morphology were investigated. The changes in biophysical properties of tumor microenvironment with change in morphology of the scaffolds were investigated. In vitro tests for proliferation, alignment and migration of normal breast epithelial cells (184B5), adenocarcinoma (MCF-7), pre-malignant (MCF10AneoT) and triple-negative (MDAMB231 on the scaffolds on days 1, 2, and 3 were carried out. The morphology of the scaffolds was characterized using FE-SEM; cell proliferation was assessed using CellTiter-Blue® Viability Assay; migration and cell-scaffold interactions were investigated using phalloidin for F-Actin and fructose response was determined by immunostaining for facilitative fructose transporter GLUT-5. Our data indicates that while topographical features affected cell adhesion and proliferation, cell lines that responded to the fructose-like probes tended to be more invasive. Furthermore, the preference to a specific scaffold was greatly altered by the presence of the probes with MDAMB231 showing least preference after 72 hours and pre-malignant AneoT showing highest preference. However, there was no significant difference in the cell numbers between scaffolds with probes and those without for the pre-malignant cells while this difference was noticeable in the control cell lines. Further investigation into specific response to glucose and fructose uptake through their major transporters GLUT2 and GLUT5 are currently ongoing. Citation Format: Carolynn Que, Samerender Nagam Hanumantharao, Brennan Vogl, Marina Tanasova, Smitha Rao. Topographical ues overlaid with fructose-like molecules to assess breast cancer recruitment in nanofiber scaffolds [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-02-11.

Electrospun Bi-layered Composite Membrane for the Removal of Metallic Contaminants in Drinking Water

Using biodegradable polymer polycaprolactone (PCL) and zeolite, the present experiment was conducted with the aim of using biodegradable PCL and zeolite based composite membrane to remove silver in drinking water. After optimizing the electrospinning parameters, a double-layered PCL and PCL/zeolite electrospun composite membranes were manufactured. The membranes were then characterized using a scanning electron microscope (SEM) and an energy dispersive X-ray (EDX) and the filtration phenomenon was conducted by dispersing silver nanoparticles in water. After comparing the filtration results using an inductively coupled plasma optical emission spectrometry (ICP-OES), it was observed that the bi-layered membrane filtered 90% of silver present in the water. The present work shows that the new PCL/zeolite based double-layered membrane can be promising to remove contaminants in drinking water.

Study of solid polymer electrolyte based on biodegradable polymer polycaprolactone

In this research the polymer electrolyte materials based on poly caprolactone (PCL) has been synthesized and characterized. Polycaprolactone is a non-toxic and biodegradable polymer that is environmentally friendly. The preparation of the polymer electrolyte film is carried out by a casting method whereby the PCL polymer is dissolved in a tetrahydrofuran (THF) solvent. Lithium perchlorate salt (LiClO4) as a source of lithium ions then was added to solution with a composition (5-40)% by weight. The solution was evaporated slowly in vacuum oven until the film was formed. The ionic conductivity, crystal structure, morphology and thermal properties of the polymer electrolyte were characterized by impedance spectroscopy X-ray diffraction (XRD) and Infrared Spectrometer (FTIR, Scanning Electron Microscope (SEM). and Differential Scanning Calorimeter (DSC) respectively. The results of the conductivity measurements showed that the PCL conductivity increased from 3.45 x 10-11 Scm-1 to 5.52 x 10-6 Scm-1 with a 30% weight salt content of LiClO4. Observations with XRD show a more amorphous polymer with more salt addition and FTIR results show that there is interaction between active groups on polymers with salt. The thermal properties show that the melting points of polymer become lower with more salt addition.

Development of a 3D-Printed Drug-Eluting Stent for Treating Obstructive Salivary Gland Disease.

Most studies of obstructive salivary gland disease have reported only statistical aspects, surgical operations, and prescriptions and have simulated the phenomena occurring in the salivary glands and ductal tissues. However, no direct lesion treatments involving drug-eluting stents have been used to reduce salivary pooling induced by inflammation. In this study, a biodegradable polymer polycaprolactone (PCL)-based antibiotic-eluting stent was developed to treat recurrent obstructive salivary gland disease. The structure's diameter was designed after consideration of the human anatomical structure, and the data were processed in a form suitable for three-dimensional (3D) printing via computer-aided design and manufacturing. After the proper mixing conditions of the antibiotics and PCL were ensured, the optimized printing conditions were secured and the stent was successfully printed with the original lumen size diameter maintained. Amoxicillin and cefotaxime, the antibiotics loaded in this study, did not lose their original antimicrobial activity under the 3D printing process and were effectively released from the constructs for verification of the antimicrobial activity against the causative bacteria according to their concentrations. In addition, antibiotic-eluting stents fabricated in a mesh-like network form were proven stable and capable of sustained release, thereby demonstrating the possibility of treating recurrent obstruction salivary gland disease.

Bioactive surface modification of polycaprolactone using MG63-conditioned medium can induce osteogenic differentiation of mesenchymal stem cells

We demonstrated an approach that modifies the scaffold surface with a range of molecules, simultaneously conjugated to the scaffold by a single treatment with concentrated conditioned medium (CM), inducing mesenchymal stem cells (MSC) to differentiate into osteogenic lineages. We first show that the CM from MG63 cells is capable of inducing the desired MSC differentiation over 7 days. We then analyze how the biodegradable polymer polycaprolactone (PCL) can be used as the scaffold. Using a CO2 plasma treatment, it is possible to conjugate MG63 CM proteins onto the PCL film surface, and we show a gradual release of protein from such a modified PCL scaffold. Finally, we verified cell differentiation and marker expression of MSCs grown on the modified PCL and show that osteogenic markers, including alkaline phosphatase and Runx2 mRNA, are significantly upregulated. Immunostaining also shows a strong expression of the Runx2 protein. Our study shows that the differentiation effects of a condition medium can be preserved when its content is used to modify the surface of polymer scaffolds. This approach may be further applied for the differentiation of various cell lines, and it provided a first step toward growing MSCs on more complex scaffold shapes aimed at therapeutic uses.

Biodegradable Polycaprolactone as Ion Solvating Polymer for Solution-Processed Light-Emitting Electrochemical Cells.

In this work, we demonstrate the use of the biodegradable polymer polycaprolactone (PCL) as the ion solvating polymer in solution-processed light-emitting electrochemical cells (LEC). We show that the inclusion of PCL in the active layer yields higher ionic conductivities and thus contributes to a rapid formation of the dynamic p-i-n junction and reduction of operating voltages. PCL shows no phase separation with the emitter polymer and reduces film roughness. The devices show light-emission at voltages as low as 3.2 V and lifetimes on the order of 30 h operating above 150 cd m−2 with turn-on times <20 s and current and luminous efficacies of 3.2 Cd A−1 and 1.5 lm W−1 respectively.

Osteogenic differentiation of human mesenchymal stem cells in the absence of osteogenic supplements: A surface-roughness gradient study

The use of biomaterials to direct osteogenic differentiation of human mesenchymal stem cells (hMSCs) in the absence of osteogenic supplements is thought to be part of the next generation of orthopedic implants. We previously engineered surface-roughness gradients of average roughness (Ra) varying from the sub-micron to the micrometer range (∼0.5–4.7μm), and mean distance between peaks (RSm) gradually varying from ∼214μm to 33μm. Here we have screened the ability of such surface-gradients of polycaprolactone to influence the expression of alkaline phosphatase (ALP), collagen type 1 (COL1) and mineralization by hMSCs cultured in dexamethasone (Dex)-deprived osteogenic induction medium (OIM) and in basal growth medium (BGM). Ra∼1.53μm/RSm∼79μm in Dex-deprived OI medium, and Ra∼0.93μm/RSm∼135μm in BGM consistently showed higher effectiveness at supporting the expression of the osteogenic markers ALP, COL1 and mineralization, compared to the tissue culture polystyrene (TCP) control in complete OIM. The superior effectiveness of specific surface-roughness revealed that this strategy may be used as a compelling alternative to soluble osteogenic inducers in orthopedic applications featuring the clinically relevant biodegradable polymer polycaprolactone. Statement of significanceBiodegradable polymers, such as polycaprolactone (PCL), are promising materials in the field of tissue engineering and regenerative medicine, which aims at creating viable options to replace permanent orthopedic implants. The material, cells, and growth-stimulating factors are often referred to as the key components of engineered tissues. In this article, we studied the hypothesis of specific surface modification of PCL being capable of inducing mesenchymal stem cell differentiation in bone cells in the absence of cell-differentiating factors. The systematic investigation of the linearly varying surface-roughness gradient showed that an average PCL roughness of 0.93μm alone can serve as a compelling alternative to soluble osteogenic inducers in orthopedic applications featuring the clinically relevant biodegradable polymer polycaprolactone.

In vitro degradation and cell attachment studies of a new electrospun polymeric tubular graft.

Electrospinning technique was utilized to engineer a small-diameter (id = 4 mm) tubular graft. The tubular graft was made from biocompatible and biodegradable polymers polycaprolactone (PCL) and poliglecaprone with 3:1 (PCL:PGC) ratio. Enzymatic degradation effect on the mechanical properties and fiber morphology in the presence of lipase enzyme were observed. Significant changes in tensile strength (1.86–1.49 MPa) and strain (245–205 %) were noticed after 1 month in vitro degradation. The fiber breakage was clearly evident through scanning electron microscopy (SEM) after 4 weeks in vitro degradation. Then, the graft was coated with a collagenous protein matrix to impart bioactivity. Human umbilical vein endothelial cells (HUVECs) and aortic artery smooth muscle cells (AoSMCs) attachment on the coated graft were observed in static condition. Further, HUVECs were seeded on the lumen surface of the grafts and exposed to laminar shear stress for 12 h to understand the cell attachment. The coated graft was aged in PBS solution (pH 7.3) at 37 °C for 1 month to understand the coating stability. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) suggested the erosion of the protein matrix from the coated graft under in vitro condition.

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.