Mixture Of Polycaprolactone Research Articles

Bilayer nanofibers loaded with Malva sylvestris extract for enhanced wound healing applications

Addressing the challenges of wound care requires accurate dressing selection. The combination of collagen with nanofibers (NFs) enhances its properties, improving cellular recognition. Multi-layered nanofibrous systems, particularly those with Polycaprolactone (PCL), offer higher mechanical attributes and prolonged substance release. We fabricated four types of nanofibrous bilayer mats (NBMs) using electrospinning (EN), each composed of an active layer containing a mixture of PCL and collagen loaded with and without Malva sylvestris (MS) extract, and an inactive layer with only PCL. The resulting bilayers were neat PCL/PCL-Collagen (PCLC), PCL/PCLC-5% MS, PCL/PCLC-10% MS, and PCL/PCLC-15% MS. Morphological and mechanical properties, porosity, water vapor transmission rate (WVTR), swelling rates, drug release profiles, cytotoxicity, cell attachment, and cytoprotective effect of bilayers were evaluated. FE-SEM imaging revealed smooth and filamentous mats without any beads, with Fiber diameter average (FDA) ranging from 128 ± 41 nm to 140 ± 51 nm. WVTR values of the NFs were comparable to commercial dressings like Tegaderm, Bioclusive, and Op Site. The mats demonstrated significant liquid uptake capacity, indicating their potential to handle wound exudate. They exhibited prolonged extract release, ensuring a sustained supply. All mats showed excellent blood compatibility, with our MS-loaded NBMs displaying rapid blood clotting times, essential for effective wound closure. FE-SEM images confirmed robust cell adhesion and spreading on both loaded and unloaded mats. The study underscored the potent cytoprotective effects of MS extract, in both free and encapsulated forms. The dose-dependent increase in cell viability suggests its potential in mitigating oxidative stress-induced cellular damage. The MTT (4,5-dimethyl- 2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay revealed that encapsulating MS extract in bilayer NFs significantly improved cell viability at 48 and 72 h, surpassing free MS extract treatment.

Peptide-Functionalized Electrospun Meshes for the Physiological Cultivation of Pulmonary Alveolar Capillary Barrier Models in a 3D-Printed Micro-Bioreactor.

In vitro environments that realize biomimetic scaffolds, cellular composition, physiological shear, and strain are integral to developing tissue models of organ-specific functions. In this study, an in vitro pulmonary alveolar capillary barrier model is developed that closely mimics physiological functions by combining a synthetic biofunctionalized nanofibrous membrane system with a novel three-dimensional (3D)-printed bioreactor. The fiber meshes are fabricated from a mixture of polycaprolactone (PCL), 6-armed star-shaped isocyanate-terminated poly(ethylene glycol) (sPEG-NCO), and Arg-Gly-Asp (RGD) peptides by a one-step electrospinning process that offers full control over the fiber surface chemistry. The tunable meshes are mounted within the bioreactor where they support the co-cultivation of pulmonary epithelial (NCI-H441) and endothelial (HPMEC) cell monolayers at air-liquid interface under controlled stimulation by fluid shear stress and cyclic distention. This stimulation, which closely mimics blood circulation and breathing motion, is observed to impact alveolar endothelial cytoskeleton arrangement and improve epithelial tight junction formation as well as surfactant protein B production compared to static models. The results highlight the potential of PCL-sPEG-NCO:RGD nanofibrous scaffolds in combination with a 3D-printed bioreactor system as a platform to reconstruct and enhance in vitro models to bear a close resemblance to in vivo tissues.

3D-Printed Barrier Membrane Using Mixture of Polycaprolactone and Beta-Tricalcium Phosphate for Regeneration of Rabbit Calvarial Defects.

Background: Polycarprolactone and beta tricalcium phosphate (PCL/β-TCP) are resorbable biomaterials that exhibit ideal mechanical properties as well as high affinity for osteogenic cells. Aim: Objective of this study was to evaluate healing and tissue reaction to the PCL/β-TCP barrier membrane in the rabbit calvaria model for guided bone regeneration. Materials and Methods: The PCL/β-TCP membranes were 3D printed. Three circular defects were created in calvaria of 10 rabbits. The three groups were randomly allocated for each specimen: (i) sham control; (ii) PCL/β-TCP membrane (PCL group); and (iii) PCL/β-TCP membrane with synthetic bone graft (PCL-BG group). The animals were euthanized after two (n = 5) and eight weeks (n = 5) for volumetric and histomorphometric analyses. Results: The greatest augmented volume was achieved by the PCL-BG group at both two and eight weeks (p < 0.01). There was a significant increase in new bone after eight weeks in the PCL group (p = 0.04). The PCL/β-TCP membrane remained intact after eight weeks with slight degradation, and showed good tissue integration. Conclusions: PCL/β-TCP membrane exhibited good biocompatibility, slow degradation, and ability to maintain space over eight weeks. The 3D-printed PCL/β-TCP membrane is a promising biomaterial that could be utilized for reconstruction of critical sized defects.

Topological, Mechanical and Biological Properties of Ti6Al4V Scaffolds for Bone Tissue Regeneration Fabricated with Reused Powders via Electron Beam Melting.

Cellularized scaffold is emerging as the preferred solution for tissue regeneration and restoration of damaged functionalities. However, the high cost of preclinical studies creates a gap between investigation and the device market for the biomedical industry. In this work, bone-tailored scaffolds based on the Ti6Al4V alloy manufactured by electron beam melting (EBM) technology with reused powder were investigated, aiming to overcome issues connected to the high cost of preclinical studies. Two different elementary unit cell scaffold geometries, namely diamond (DO) and rhombic dodecahedron (RD), were adopted, while surface functionalization was performed by coating scaffolds with single layers of polycaprolactone (PCL) or with mixture of polycaprolactone and 20 wt.% hydroxyapatite (PCL/HA). The mechanical and biological performances of the produced scaffolds were investigated, and the results were compared to software simulation and experimental evidence available in literature. Good mechanical properties and a favorable environment for cell growth were obtained for all combinations of scaffold geometry and surface functionalization. In conclusion, powder recycling provides a viable practice for the biomedical industry to strongly reduce preclinical costs without altering biomechanical performance.

Custom-made artificial eyes using 3D printing for dogs: A preliminary study.

Various incurable eye diseases in companion animals often result in phthisis bulbi and eye removal surgery. Currently, the evisceration method using silicone balls is useful in animals; however, it is not available to those with impaired cornea or severe ocular atrophy. Moreover, ocular implant and prostheses are not widely used because of the diversity in animal size and eye shape, and high manufacturing cost. Here, we produced low-cost and customized artificial eyes, including implant and prosthesis, using computer-aided design and three-dimensional (3D) printing technique. For 3D modeling, the size of the artificial eyes was optimized using B-mode ultrasonography. The design was exported to STL files, and then printed using polycaprolactone (PCL) for prosthesis and mixture of PCL and hydroxyapatite (HA) for ocular implant. The 3D printed artificial eyes could be produced in less than one and half hour. The prosthesis was painted using oil colors and biocompatible resin. Two types of eye removal surgery, including evisceration and enucleation, were performed using two beagle dogs, as a preliminary study. After the surgery, the dogs were clinically evaluated for 6 months and then histopathological evaluation of the implant was done. Ocular implant was biocompatible and host tissue ingrowth was induced after in vivo application. The custom-made prosthesis was cosmetically excellent. Although long-term clinical follow-up might be required, the use of 3D printed-customized artificial eyes may be beneficial for animals that need personalized artificial eye surgery.

Development of a Curcumin-Loaded Polymeric Microparticulate Oral Drug Delivery System for Colon Targeting by Quality-by-Design Approach.

The purpose of this study was to apply the quality-by-design (QbD) approach for the development of colon-targeted curcumin-loaded polymeric microparticles (Col-CUR-MPs). The proportion of the enterosoluble polymer (Eudragit® FS) in the polymeric matrix, curcumin concentration, and the concentration of the polymer mixture (Eudragit® FS-polycaprolactone) were identified as potential risk factors for the quality of the final product following risk assessment. The influence of these variables on the critical quality attributes (CQAs) of Col-CUR-MPs was investigated. Therefore, a central composite face experimental design was used in order to determine the functional relationships between variables and product CQAs. The obtained regression model and contour plots were used to establish the design space. Finally, the model was validated by preparing two microparticulate formulations, one corresponding to the robust setpoint from within the design space and one outside the established design space, and calculating the percentage bias between the experimental and predicted values. The in vivo study, which was conducted on a fluorescein-loaded formulation that corresponded to the robust setpoint determined by QbD and that contained a mixture of polycaprolactone and Eudragit® FS (60:40, w/w), confirmed the colon-targeting qualities of this formulation.

Development of Thermo-Responsive Polycaprolactone-Polydimethylsiloxane Shrinkable Nanofibre Mesh.

A thermally activated shape memory polymer based on the mixture of polycaprolactone (PCL) and polydimethylsiloxane (PDMS) was fabricated into the nanofibre mesh using the electrospinning process. The added percentages of the PDMS segment in the PCL-based polymer influenced the mechanical properties. Polycaprolactone serves as a switching segment to adjust the melting temperature of the shape memory electro-spun PCL–PDMS scaffolds to our body temperature at around 37 °C. Three electro-spun PCL–PDMS copolymer nanofibre samples, including PCL6–PDMS4, PCL7–PDMS3 and PCL8–PDMS2, were characterised to study the thermal and mechanical properties along with the shape memory responses. The results from the experiment showed that the PCL switching segment ratio determines the crystallinity of the copolymer nanofibres, where a higher PCL ratio results in a higher degree of crystallinity. In contrast, the results showed that the mechanical properties of the copolymer samples decreased with the PCL composition ratio. After five thermomechanical cycles, the fabricated copolymer nanofibres exhibited excellent shape memory properties with 98% shape fixity and above 100% recovery ratio. Moreover, biological experiments were applied to evaluate the biocompatibility of the fabricated PCL–PDMS nanofibre mesh. Owing to the thermally activated shape memory performance, the electro-spun PCL–PDMS fibrous mesh has a high potential for biomedical applications such as medical shrinkable tubing and wire.

Facile fabrication of gelatin and polycaprolactone based bilayered membranes via spin coating method with antibacterial and cyto-compatible properties

A growth of bacterial infections and over-and inefficient release of antibiotics forces one to search new antibacterial agents and/or strategies. In this study, a novel strategy towards biocompatible and antibacterial bilayer wound dressing was proposed by a two-step spin coating method combined with in-situ crosslinking polymerization. First, through in-situ crosslinking polymerization, [2-(methacryloyloxy) ethyl] trimethylammonium chloride ([MTA][Cl]) was polymerized and crosslinked in polycaprolactone (PCL) solution and PCL/PMTA solution was obtained. Then, the PCL/PMTA solution was spinning-coated as the antibacterial top layer and the mixture of PCL and gelatin (Gel) (PCL/Gel) as the biocompatible bottom layer. The obvious bi-layered structure and boundary between the two layers was distinctly showed in scanning electron microscope (SEM) pictures. X-ray diffraction (XRD), attenuated total reflection flourier transformed infrared spectroscopy (ATR-FTIR), differential scanning calorimeter (DSC), thermo-gravimetric analysis (TGA) and water contact angle (WCA) analysis were used to investigate the physical and chemical properties and obtained results demonstrated the successful preparation of the bi-layered membranes. The prepared bi-layered wound dressing displayed both strong antibacterial activity and good biocompatibility in vitro. The bilayered membranes with biocompatible and antibacterial properties would be next generation of wound dressing.

Quercetin-loaded and unloaded electrospun membranes: Synthesis, characterization and in vitro release study

Electrospun fiber membranes have been utilized to delivery hydrophilic/hydrophobic drugs in the drug delivery systems. They offer several features such as high surface area to volume ratio, high porosity and high productivity. In this paper, quercetin (QU)-loaded and unloaded electrospun membranes were prepared via electrospinning of polycaprolactone (PCL) blended with polyethylene oxide (PEO), polylactic acid (PLA), and polylactic-co-glycolic acid (PLGA). The prepared membranes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and drop shape analysis (DSA). In vitro release of QU from the QU-loaded membranes was examined in simulated physiological condition by ultraviolet–visible spectroscopy. The results of morphological analysis revealed that electrospun membrane prepared by the mixture of PCL and PEO polymers with QU had more smooth, beadless and random morphology. Due to the release study, the highest amount of QU release was obtained within 240 min period. In addition, in vitro cytotoxicity study indicated that the QU-loaded membranes exhibited toxicity on human breast carcinoma cells in 24 h. These results showed that quercetin-loaded PCL and PEO membranes can be used in drug delivery systems as a drug carrier vehicle.

PCL/PVA nanofibrous scaffold improve insulin-producing cells generation from human induced pluripotent stem cells

Pancreatic differentiation of stem cells will aid treatment of patients with type I diabetes mellitus (T1DM). Synthetic biopolymers utilization provided extracellular matrix (ECM) and desired attributes in vitro to enhance conditions for stem cells proliferation, attachment and differentiation. A mixture of polycaprolactone and polyvinyl alcohol (PCL/PVA)-based scaffold, could establish an in vitro three-dimensional (3D) culture model. The objective of this study was investigation of the human induced pluripotent stem cells (hiPSCs) differentiation capacity to insulin-producing cells (IPCs) in 3D culture were compared with conventional culture (2D) groups evaluated at the mRNA and protein levels by quantitative PCR and immunofluorescence assay, respectively. The functionality of differentiated IPCs was assessed by C-peptide and insulin release in response to glucose stimulation test. Real-Time PCR results showed that iPSCs-IPCs expressed pancreas-specific transcription factors (Insulin, Pdx1, Glucagon, Glut2 and Ngn3). The expressions of these transcription factors in PCL/PVA scaffold were higher than 2D groups. In addition to IPCs specific markers were detected by immunochemistry. These cells in both groups secreted insulin and C-peptide in a glucose challenge test by ELISA showing in vitro maturation. The results of current study demonstrated that enhanced differentiation of IPCs from hiPSCs could be result of PCL/PVA nanofibrous scaffolds. In conclusion, this research could provide a new approach to beta-like cells replacement therapies and pancreatic tissue engineering for T1DM in the future.

Fabrication and Characterization of Magnesium Ferrite-Based PCL/Aloe Vera Nanofibers.

Composite nanofibers of biopolymers and inorganic materials have been widely explored as tissue engineering scaffolds because of their superior structural, mechanical and biological properties. In this study, magnesium ferrite (Mg-ferrite) based composite nanofibers were synthesized using an electrospinning technique. Mg-ferrite nanoparticles were first synthesized using the reverse micelle method, and then blended in a mixture of polycaprolactone (PCL), a synthetic polymer, and Aloe vera, a natural polymer, to create magnetic nanofibers by electrospinning. The morphology, structural and magnetic properties, and cellular compatibility of the magnetic nanofibers were analyzed. Mg-ferrite/PCL/Aloe vera nanofibers showed good uniformity in fiber morphology, retained their structural integrity, and displayed magnetic strength. Experimental results, using cell viability assay and scanning electron microscopy imaging showed that magnetic nanofibers supported 3T3 cell viability. We believe that the new composite nanofibrous membranes developed in this study have the ability to mimic the physical structure and function of tissue extracellular matrix, as well as provide the magnetic and soluble metal ion attributes in the scaffolds with enhanced cell attachment, and thus improve tissue regeneration.

Effect of the incorporation of chitosan on the physico-chemical, mechanical properties and biological activity on a mixture of polycaprolactone and polyurethanes obtained from castor oil.

In the present study, polyurethane materials were obtained from castor oil, polycaprolactone and isophorone diisocyanate by incorporating different concentrations of chitosan (0.5, 1.0 and 2.0% w/w) as an additive to improve the mechanical properties and the biological activity of polyurethanes. The polyurethanes were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, stress/strain fracture tests and swelling analysis, and the hydrophilic character of the surface was determined by contact angle trials. The objectives of the study were to evaluate the effect of the incorporation of chitosan on the changes of the physico-chemical and mechanical properties and the invitro biological activity of the polyurethanes. It was found that the incorporation of chitosan enhances the ultimate tensile strength of the polyurethanes and does not affect the strain at fracture in polyurethanes with 5% w/w of polycaprolactone and concentrations of chitosan ranging from 0 to 2% w/w. In addition, PCL5-Q-PU formulations and their degradation products did not affect cell viability of L929 mouse fibroblast and 3T3, respectively. Polyurethane formulations showed antibacterial activities against Staphylococcus aureus and Escherichia coli bacteria. The results of this study have highlighted the potential biomedical application of this polyurethanes related to soft and cardiovascular tissues.

Sintering of compound nonwovens by forced convection of hot air

Sintering and interlocking of model nonwoven materials composed of a mixture of polycaprolactone (PCL) and polyacrylonitrile (PAN) fibers by means of forced convection of hot air through their pores is studied experimentally and theoretically. PCL has a much lower melting point than PAN, and the air temperature was sufficiently high to melt the former, while the latter stayed solid. These molten PCL fibers became a binder and conglutinated the PAN matrix, enhancing stiffness. This was demonstrated by measuring the effect of heat treatment on the resulting Young’s modulus of these compound nonwovens, as well as by the corresponding micro-morphological changes revealed by scanning electron microscopy. It was also shown that heating past the melting point of the binding fibers (PCL) would not further increase stiffness of the nonwovens, neither would heating for longer periods of times. A theoretical model describing the heating process was developed and tested experimentally. The model was verified using poly(ethylene terephthalate) PET nonwovens, which revealed good agreement of the data with the theoretical predictions.

Pcl/Peg Electrospun Fibers as Drug Carriers for the Controlled Delivery of Dipyridamole

Electrospinning is a versatile and diverse technology for the production of nano- and microfibers that can be used as a drug delivery system (DDS). The aim of this study was to create fibrous scaffolds from a mixture of polycaprolactone (PCL) and polyethylene glycol (PEG) and to evaluate the suitability of the fibers as DDS. Dipyridamole (DPA), an anti-thrombotic and anti-proliferative pharmaceutical agent, was used as a model drug. Two types of PEG with different chain length were used. The structural, mechanical and physicochemical characteristics of the fibers with and without DPA, were determined, and the release kinetics of DPA were studied. The obtained fibers loaded with DPA and with the higher molecular weight PEG were smooth and had an average diameter of 586.75 ± 204.79 nm and an average Young’s modulus of 57.14 ± 4.35 MPa, whereas the tensile strain at break was 0.61 ±0.05 mm/mm and the ultimate tensile strength (UTS) was 16.79 ± 3.08 MPa. The cumulative release of DPA revealed two stages: an initial burst phenomenon followed by slower Fickian diffusion (release exponent n = 0.432).

Fabrication Process of Polymer Nano-Composite Filament for Fused Deposition Modeling

This Report Describe the Development of a New Polymer Nano-Composite Material that Tobe Used as an Altenative Material for Fused Deposition Modeling (FDM) Process. this New Type Ofpolymer Nano-Composites is a Mixture of Polycaprolactone (PCL) as a Main Resin, Montmorillonite(MMT) and Hydroxyapatite (HA) as a Filler. the Compunding Process is Done Using Single Screwextruder Nanomixer Machine. then the Compounded Polymer Nano-Composites is Crushed and Fedinto Single Screw Extruder which is Design to Produce a Filament. A Polymer Nano-Compositesfilament with 1.7 Mm of was Successfully Produced by Assisted of Water Bath and Puller Machine.The Temperature Setting for Heater 1, Heater 2, Heater 3 and Heater 4 on Extruder Machine Are78°C, 114°C, 113°C, and 79°C Respectively. the Spindle Speed for Extruder Machine was Set to 3.0Hz, while the Puller Machine Speed is 2.5%.

Fabrication of electrospun biocomposites comprising polycaprolactone/fucoidan for tissue regeneration

In this study, we designed a new biocomposite comprising electrospun polycaprolactone (PCL)/fucoidan, in which the fucoidan has various beneficial biological functions, including anticoagulant, antiviral, and immunomodulatory activity. To obtain the composite scaffolds, a mixture of PCL and fucoidan was electrospun using various compositions (1, 2, 3, and 10wt.%) of fucoidan powders. The resultant electrospun composites exhibited improved tensile modulus and strength for limited weight fractions (<10wt.%) of fucoidan when compared with the pure PCL fiber mats. In addition, the biocomposites showed dramatic hydrophilic properties at >3wt.% of fucoidan in the PCL/fucoidan. The biocompatibility of the electrospun mats was examined in vitro using osteoblast-like cells (MG63). Total protein content, alkaline phosphatase activity, and calcium mineralization were assessed. Scanning electron microscopic images showed that the cells were distributed more widely and were agglomerated on PCL/fucoidan mats compared with pure PCL mats. In addition, total protein content, alkaline phosphatase activity, and calcium mineralization were higher with PCL/fucoidan mats than with pure PCL mats. These observations suggest that fucoidan-supplemented biocomposites would make excellent materials for tissue-engineering applications.

Mesenchymal Stem Cell Responses to Bone-Mimetic Electrospun Matrices Composed of Polycaprolactone, Collagen I and Nanoparticulate Hydroxyapatite

The performance of biomaterials designed for bone repair depends, in part, on the ability of the material to support the adhesion and survival of mesenchymal stem cells (MSCs). In this study, a nanofibrous bone-mimicking scaffold was electrospun from a mixture of polycaprolactone (PCL), collagen I, and hydroxyapatite (HA) nanoparticles with a dry weight ratio of 50/30/20 respectively (PCL/col/HA). The cytocompatibility of this tri-component scaffold was compared with three other scaffold formulations: 100% PCL (PCL), 100% collagen I (col), and a bi-component scaffold containing 80% PCL/20% HA (PCL/HA). Scanning electron microscopy, fluorescent live cell imaging, and MTS assays showed that MSCs adhered to the PCL, PCL/HA and PCL/col/HA scaffolds, however more rapid cell spreading and significantly greater cell proliferation was observed for MSCs on the tri-component bone-mimetic scaffolds. In contrast, the col scaffolds did not support cell spreading or survival, possibly due to the low tensile modulus of this material. PCL/col/HA scaffolds adsorbed a substantially greater quantity of the adhesive proteins, fibronectin and vitronectin, than PCL or PCL/HA following in vitro exposure to serum, or placement into rat tibiae, which may have contributed to the favorable cell responses to the tri-component substrates. In addition, cells seeded onto PCL/col/HA scaffolds showed markedly increased levels of phosphorylated FAK, a marker of integrin activation and a signaling molecule known to be important for directing cell survival and osteoblastic differentiation. Collectively these results suggest that electrospun bone-mimetic matrices serve as promising degradable substrates for bone regenerative applications.

An electrospun triphasic nanofibrous scaffold for bone tissue engineering

A nanofibrous triphasic scaffold was electrospun from a mixture of polycaprolactone (PCL), type-I collagen and hydroxyapatite nanoparticles (nano-HA) with a mixture dry weight ratio of 50/30/20, respectively. Scaffolds were characterized by evaluating fiber morphology and chemical composition, dispersion of HA particles and nanoindentation. Scanning electron microscopy revealed fibers with an average diameter of 180 ± 50 nm, which coincides well with the collagen fiber bundle diameter characteristic of the native extracellular matrix of bone. The triphasic fibers, stained with calcein and imaged with confocal microscopy, show a uniform dispersion of apatite particles throughout their length with minor agglomeration. Scaffold fibers of triphasic (50/30/20), collagen/nano-HA (80/20), PCL/nano-HA (80/20), pure PCL and pure collagen were each pressure consolidated into non-porous pellets for evaluation by transmission electron microscopy and nanoindentation. While the majority of apatite particles are uniformly dispersed having an average size of 30 nm, agglomerated particles as large as a few microns are sparsely distributed. Nanoindentation of the pressure-consolidated scaffolds showed a range of Young's modulus (0.50–3.9 GPa), with increasing average modulus in the order of (PCL < PCL/nano-HA < collagen < triphasic < collagen/nano-HA). The modulus data emphasize the importance of collagen and its interaction with other components in affecting mechanical properties of osteoconductive scaffolds.