Polycaprolactone Nanofibers Research Articles

Real-Time Wireless Sensing of Cardiomyocyte Contractility by Integrating Magnetic Microbeam and Oriented Nanofibers.

In vitro cardiomyocyte mechano-sensing platform is crucial for evaluating the mechanical performance of cardiac tissues and will be an indispensable tool for application in drug discovery and disease mechanism study. Magnetic sensing offers significant advantages in real-time, in situ wireless monitoring and resistance to ion interference. However, due to the mismatch between the stiffness of traditional rigid magnetic material and myocardial tissue, sensitivity is insufficient and it is difficult to achieve cell structure induction and three-dimensional cultivation. Herein, a magnetic sensing platform that integrates a neodymium-iron-boron/polydimethylsiloxane (NdFeB/PDMS) flexible microbeam with suspended and ordered polycaprolactone (PCL) nanofiber membranes was developed, providing a three-dimensional anisotropic culture environment for cardiomyocyte growth and simultaneously realizing in situ wireless contractility monitoring. The as-prepared sensor presented an ultrahigh sensitivity of 442.2 μV/μm and a deflection resolution of 2 μm. By continuously monitoring the cardiomyocyte growth status and drug stimulation feedback, we verified the capability of the platform to capture dynamic changes in cardiomyocyte contractility. This platform provides a perspective tool for evaluating cardiomyocyte maturity and drug performance.

Fibrin-Polycaprolactone Scaffolds for the Differentiation of Human Neural Progenitor Cells into Dopaminergic Neurons.

Parkinson's disease (PD), a progressive central nervous system disorder marked by involuntary movements, poses a significant challenge in neurodegenerative research due to the gradual degeneration of dopaminergic (DA) neurons. Early diagnosis and understanding of PD's pathogenesis could slow disease progression and improve patient management. In vitro modeling with DA neurons derived from human-induced pluripotent stem cell-derived neural progenitor cells (NPCs) offers a promising approach. These neurons can be cultured on electrospun (ES) nanofibrous polycaprolactone (PCL) scaffolds, but PCL's hydrophobic nature limits cell adhesion. We investigated the ability of ES PCL scaffolds coated with hydrophilic extracellular matrix-based biomaterials, including cell basement membrane proteins, Matrigel, and Fibrin, to enhance NPC differentiation into DA neurons. We hypothesized that fibrin-coated scaffolds would maximize differentiation based on fibrin's known benefits in neuronal tissue engineering. The scaffolds both coated and uncoated were characterized using scanning electron microscopy (SEM), transmission electron microscopy, Fourier transform infrared spectroscopy-attenuated total reflectance, and dynamic mechanical analysis to assess their properties. NPCs were seeded on the coated scaffolds, differentiated, and matured into DA neurons. Immunocytochemistry targeting tyrosine hydroxylase (TH) and SEM confirmed DA neuronal differentiation and morphological changes. Electrophysiology via microelectrode array recorded their neuronal firing. Results showed enhanced neurite extension, increased TH expression, and active electrical activity in cells on fibrin-coated scaffolds. Diluted fibrin coatings particularly promoted more pronounced neuronal differentiation and maturation. This study introduces a novel tissue-on-a-chip platform for neurodegenerative disease research using DA neurons.

High-performance triboelectric nanogenerator based on biocompatible electrospun polycaprolactone nanofiber and counter convex PDMS for low-frequency mechanical energy harvesting

High-performance triboelectric nanogenerator based on biocompatible electrospun polycaprolactone nanofiber and counter convex PDMS for low-frequency mechanical energy harvesting

A new design of an electrospinning apparatus for tissue engineering applications.

The electrospinning technique is being widely explored in the biomedical field due to its simplicity to produce meshes and its capacity to mimic the micro-nanostructure of the natural extracellular matrix. For skin tissue engineering applications, wound dressings made from electrospun nanofibers present several advantages compared to conventional dressings, such as the promotion of the hemostasis phase, wound exudate absorption, semi-permeability, easy conformability to the wound, functional ability and no scar induction. Despite being a relatively simple technique, electrospinning is strongly influenced by polymer solution characteristics, processing parameters and environmental conditions, which strongly determine the production of fibers and their morphology. However, most electrospinning systems are wrongly designed, presenting a large number of conductive components that compromises the stability of the spinning process. This paper presents a new design of an electrospinning system solving the abovementioned limitations. The system was assessed through the production of polycaprolactone (PCL) and gelatin nanofibers. Different solvents and processing parameters were considered. Results show that the proposed electrospinning system is suitable to produce reproducible and homogeneous electrospun fibers for tissue engineering applications.

An Easy Nanopatch Promotes Peripheral Nerve Repair through Wireless Ultrasound‐Electrical Stimulation in a Band‐Aid‐Like Way

AbstractLow‐intensity pulsed ultrasound (LIPUS) and electrical stimulation (ES) are effective methods that promote neural repair. However, ES usually requires electrode implantation and a power supply, which are an inconvenience to future applications. Meanwhile, it is difficult to combine ultrasound and ES through traditional methods. Herein, a nanopatch consisting of an oriented barium titanate (BTO)‐incorporated polycaprolactone (PCL) nanofiber membrane for electricity generation and a layer of graphene oxide (GO)‐doped gelatin methacryloyl (GelMA) for neural interaction is developed. This band‐aid‐like BTO@PCL/GO@GelMA nanopatch has an excellent piezoelectric performance. In vitro, the nanopatches significantly promote axonal growth under LIPUS treatment. In a rat model of erectile dysfunction caused by peripheral nerve injury, the nanopatch is easily attached to a damaged nerve similar to a band‐aid. With the assistance of ultrasound, some mechanical energy is converted into electricity by the nanopatch, and synergistic neural stimulation of ultrasound and electricity is achieved. In this way, the nanopatch significantly promoted corpus cavernosum nerve repair, resulting in the improvement of tissue structure and erectile function as well as increased conception rate in female rats. In conclusion, the nanopatch offers a synergistic ultrasound‐ES for nerve repair easily and represents a novel strategy for peripheral nerve repair.

Surface-Conjugated Galactose on Electrospun Polycaprolactone Nanofibers: An Innovative Scaffold for Uterine Tissue Engineering.

The uterus, a vital organ in the female reproductive system, nurtures and supports developing embryos until maturity. This study focuses on addressing uterine related problems by creating a nanofibrous scaffold to regenerate uterine myometrial tissue, closely resembling the native extracellular matrix (ECM) for enhanced efficacy. To achieve this, we utilized polycaprolactone (PCL) as a biomaterial and employed an electrospinning technique to generate PCL nanofibers in both random and aligned orientations. Due to the inherent hydrophobic nature of PCL nanofibers, a two-step wet chemistry surface modification technique is used, involving the conjugation of galactose onto them. Galactose, a lectin-binding sugar, was chosen to enhance the scaffold's hydrophilicity, thereby improving cell adhesion and fostering l-selectin-based interactions between the scaffold and uterine cells. These interactions, in turn, activated uterine fibroblasts, leading to ECM remodeling. The optimized electrospinning process successfully generated random and aligned nanofibers. Subsequent surface modification was carried out, and the modified scaffold was subjected to various physicochemical characterization, such as the ninhydrin assay, enzyme-linked lectin assay techniques that revealed successful galactose conjugation, and mechanical characterization to assess any changes in material bulk properties resulting from the modification. The tensile strength of random galactose-modified PCL fibers reached 0.041 ± 0.01 MPa, outperforming random unmodified PCL fibers (0.026 ± 0.01 MPa), aligned unmodified PCL fibers (0.011 ± 0.001 MPa), and aligned modified PCL fibers (0.016 ± 0.002 MPa). Cytocompatibility studies with human uterine fibroblast cells showed enhanced viability and proliferation on the modified scaffolds. Initial pilot studies were attempted in the current study involving subcutaneous implantation in the dorsal area of Wistar rats to assess biocompatibility and tissue response before proceeding to intrauterine implantation indicated that the modification did not induce adverse inflammation in vivo. In conclusion, our study introduces a surface-modified PCL nanofibrous material for myometrial tissue engineering, offering promise in addressing myometrial damage and advancing uterine health and reproductive well-being.

D@MSNs-P/PCL antibacterial nanofibers combined with DBD cold plasma for fresh pork preservation

Fresh pork is easily contaminated by microorganisms, leading to spoilage. Dielectric barrier discharge (DBD) cold plasma technology has shown significant advantages in the preservation of meat. However, severe lipid oxidation of pork resulting from DBD treatment greatly limits its development. Herein, the antibacterial D@MSNs-P/PCL nanofiber membranes were prepared by modification polycaprolactone (PCL) with pre-reported nanomaterials (D@MSNs-P) through electrostatic spinning. Compared with the PCL membranes, the D@MSNs-P/PCL membranes showed better water stability, lower water vapor transmission rate, stronger hydrophobicity, and potent antibacterial activity. The D@MSNs-P/PCL membranes can be used for wrapping fresh pork before treatment with DBD plasma, which can not only improve the antibacterial efficiency but effectively inhibit the lipid oxidation and color change of fresh pork, extending the shelf life for 2 days. The developed D@MSNs-P/PCL membranes can also be used alone to preserve other fresh meat or oily food, with a wide range of application prospects.

Novel shish-kebab structured nanofibrous decorating chitosan unidirectional scaffolds to mimic extracellular matrix for tissue engineering

Electrospun nanofibrous scaffolds are renowned for their ability to mimic the microstructure of the extracellular matrix (ECM). However, they often fail to replicate the geometry of target tissues, and the biocompatibility of these scaffolds those made from synthetic polymers is always limited due to the lack of cell binding sites. To address these issues, we proposed an innovative approach that combined unidirectional freeze-drying and electrospinning. During this process, electrospun polycaprolactone (PCL) nanofibers were chopped into nanofibrils, which range in size up to several hundred micrometers, and were incorporated into the chitosan scaffolds via unidirectional freeze-drying. In these scaffolds, the chitosan phase was responsible for maintaining the structural integrity at the macroscale, while the embedded nanofibers enhanced the surface topography at the microscale. The resulting scaffolds exhibited a high porosity of 90% and an impressive water uptake capacity of 2500%. Furthermore, 3T3 fibroblast cells showed strong interactions with the scaffolds, characterized by high rates of cell proliferation and viability. The cells also displayed significant orientation along the direction of the pores, suggesting that the scaffolds effectively guided cellular growth.

Enhancement of the chondrogenic differentiation capacity of human dental pulp stem cells via chondroitin sulfate-coated polycaprolactone-MWCNT nanofibers

Most of the conditions involving cartilaginous tissues are irreversible and involve degenerative processes. The aim of the present study was to fabricate a biocompatible fibrous and film scaffolds using electrospinning and casting techniques to induce chondrogenic differentiation for possible application in cartilaginous tissue regeneration. Polycaprolactone (PCL) electrospun nanofibrous scaffolds and PCL film were fabricated and incorporated with multi-walled carbon nanotubes (MWCNTs). Thereafter, coating of chondroitin sulfate (CS) on the fibrous and film structures was applied to promote chondrogenic differentiation of human dental pulp stem cells (hDPSCs). First, the morphology, hydrophilicity and mechanical properties of the scaffolds were characterized by scanning electron microscopy (SEM), spectroscopic characterization, water contact angle measurements and tensile strength testing. Subsequently, the effects of the fabricated scaffolds on stimulating the proliferation of human dental pulp stem cells (hDPSCs) and inducing their chondrogenic differentiation were evaluated via electron microscopy, flow cytometry and RT‒PCR. The results of the study demonstrated that the different forms of the fabricated PCL-MWCNTs scaffolds analyzed demonstrated biocompatibility. The nanofilm structures demonstrated a higher rate of cellular proliferation, while the nanofibrous architecture of the scaffolds supported the cellular attachment and differentiation capacity of hDPSCs and was further enhanced with CS addition. In conclusion, the results of the present investigation highlighted the significance of this combination of parameters on the viability, proliferation and chondrogenic differentiation capacity of hDPSCs seeded on PCL-MWCNT scaffolds. This approach may be applied when designing PCL-based scaffolds for future cell-based therapeutic approaches developed for chondrogenic diseases.

Synthesis of Nanosized γ‐Cyclodextrin Metal‐Organic Frameworks as Carriers of Limonene for Fresh‐Cut Fruit Preservation Based on Polycaprolactone Nanofibers (Small 29/2024)

Synthesis of Nanosized γ‐Cyclodextrin Metal‐Organic Frameworks as Carriers of Limonene for Fresh‐Cut Fruit Preservation Based on Polycaprolactone Nanofibers (Small 29/2024)

Uridine-Loaded Polycaprolactone Nanofiber Mats as a Novel Wound Dressing

In the current study, a novel wound dressing material for an effective wound healing was developed by loading Uridine (URD), an endogenous compound known for its regenerative properties, into polycaprolactone (PCL) nanofibers. Initially, PCL nanofibers without URD were fabricated from different PCL solutions (7, 8, 10 and 11% w/w) by electrospinning and optimum PCL concentration (10% w/w) for URD loading was determined. After loading URD at different concentrations (0.1, 0.5 and 1% w/w) into 10% PCL solution, PCL/URD nanofibers were electrospun. Structural characteristics, release kinetics as well as in vitro and in vivo effects of the PCL/URD nanofibers were studied and in vivo effects were compared with a conventional wound dressing material. Loading URD increased nanofiber diameters from 248 to 509 nm and decreased contact angles from 123.76° to 94.3° with increasing URD concentrations. URD showed a burst release in the first 60 min following a more gradual release up to the 5th day which best fitted with Korsmeyer–Peppas model. PCL/URD mats provided enhanced viability in vitro in MTT assay using mouse L929 fibroblast cell line. Furthermore, in vivo wound closure studies revealed an immediate and robust wound healing in rats treated with PCL/URD mats compared to PCL mats without URD as well as the conventional wound dressing material. These data suggest that URD-loaded PCL nanofiber mats are promising materials as wound dressing.Graphical abstract

The polycaprolactone and silk fibroin nanofibers with Janus-structured sheaths for antibacterial and antioxidant by loading Taxifolin

Electrospinning is a widely recognized method for producing Janus or core-shell nanofibers. In this study, nanofibrous membranes were fabricated through co-axial electrospinning utilizing polycaprolactone (PCL) and silk fibroin (SF) as the Janus shell, and taxifolin (TAX) and SF as the core. The resulting nanofibers had diameters of 816 ± 161 nm and core diameters of 73 ± 5 nm. The morphology and properties of the PCL-SF@SF/TAX nanofibers were subsequently analyzed. The results demonstrated that the nanofibrous membranes achieved physical and chemical characteristics potential for tissue engineering and drug delivery. Specifically, the membranes exhibited a Young's modulus of 9.64 ± 0.29 MPa, a water contact angle of 79.1 ± 1.3°, and a weight loss of 17.3 ± 1.0 % over a period of 28 days. The incorporation of TAX endowed the membranes with antibacterial properties, effectively combating Escherichia coli and Staphylococcus aureus. Furthermore, the membranes demonstrated antioxidant capabilities, with a DPPH radical scavenging efficiency of 38.5 ± 5.6 % and a Trolox-equivalent antioxidant capacity of 0.24 ± 0.01 mM. The release of the antioxidant was sustained over 28 days, following first-order release kinetics. The nanofibrous membranes, referred to as PSST, exhibit promising potential for use as biomaterials, characterized by their antibacterial activity, antioxidant and cytocompatibility.

Stimuli-Responsive Codelivery System-Embedded Polymeric Nanofibers with Synergistic Effects of Growth Factors and Low-Intensity Pulsed Ultrasound to Enhance Osteogenesis Properties.

The present work aims to develop optimized scaffolds for bone repair by incorporating mesoporous nanoparticles into them, thereby combining bioactive factors for cell growth and preventing rapid release or loss of effectiveness. We synthesized biocompatible and biodegradable scaffolds designed for the controlled codelivery of curcumin (CUR) and recombinant human bone morphogenic protein-2 (rhBMP-2). Active agents in dendritic silica/titania mesoporous nanoparticles (DSTNs) were incorporated at different weight percentages (0, 2, 5, 7, 9, and 10 wt %) into a matrix of polycaprolactone (PCL) and polyethylene glycol (PEG) nanofibers, forming the CUR-BMP-2@DSTNs/PCL-PEG delivery system (S0, S2, S5, S7, S9, and S10, respectively, with the number showing the weight percentage). To enhance the formation process, the system was treated using low-intensity pulsed ultrasound (LIPUS). Different advanced methods were employed to assess the physical, chemical, and mechanical characteristics of the fabricated scaffolds, all confirming that incorporating the nanoparticles improves their mechanical and structural properties. Their hydrophilicity increased by approximately 25%, leading to ca. 53% enhancement in their water absorption capacity. Furthermore, we observed a sustained release of approximately 97% for CUR and 70% for BMP-2 for the S7 (scaffold with 7 wt % DSTNs) over 28 days, which was further enhanced using ultrasound. In vitro studies demonstrated accelerated scaffold biodegradation, with the highest level observed in S7 scaffolds, approximately three times higher than the control group. Moreover, the cell viability and proliferation on DSTNs-containing scaffolds increased when compared to the control group. Overall, our study presents a promising nanocomposite scaffold design with notable improvements in structural, mechanical, and biological properties compared to the control group, along with controlled and sustained drug release capabilities. This makes the scaffold a compelling candidate for advanced bone tissue engineering and regenerative therapies.

Fast and sustainable production of smart nanofiber mats by solution blow spinning for food quality monitoring: Potential of polycaprolactone and agri-food residue-derived anthocyanins

The shelf life of perishable foods is estimated through expensive and imprecise analyses that do not account for improper storage. Smart packaging, obtained by agile manufacturing of nanofibers functionalized with natural pigments from agri-food residues, presents promising potential for real-time food quality monitoring. This study employed the solution blow spinning (SBS) technique for the rapid production of smart nanofiber mats based on polycaprolactone (PCL), incorporating extracts of agricultural residues rich in anthocyanins from eggplant (EE) or purple cabbage (CE) for monitoring food quality. The addition of EE or CE to the PCL matrix increased the viscosity of the solution and the diameter of the nanofibers from 156 nm to 261–370 nm. The addition of extracts also improved the mechanical and water-related properties of the nanofibers, although it reduced the thermal stability. Attenuated total reflectance Fourier-transform infrared spectroscopy confirmed the incorporation of anthocyanins into PCL nanofibers. Nanofiber mats incorporated with EE or CE exhibited visible color changes (ΔE ≥ 3) in response to buffer solutions (pH between 3 and 10), and ammonia vapor. Smart nanofibers have demonstrated the ability to monitor fish fillet spoilage through visible color changes (ΔE ≥ 3) during storage. Consequently, smart nanofibers produced by the SBS technique, using PCL and anthocyanins from agro-industrial waste, reveal potential as smart packaging materials for food.

Equisetum arvense and nano zinc oxide‐infused polycaprolactone scaffolds: A multifaceted approach for antibacterial, antioxidant, and hemocompatible wound dressing

AbstractAn appropriate skin tissue‐engineered scaffold can act promptly to combat microbial infection and preserve the wound throughout all phases of healing. To achieve sufficient healing, scaffolds should also promote cell proliferation and regeneration. Therefore, it has become essential to develop skin tissue engineering scaffolds that mimic the extracellular matrices of the skin, provide a high porosity scaffold structure, and act as an antimicrobial protection during wound healing. In this study, the polycaprolactone (PCL) electrospun scaffold was modified with optimal amounts of zinc oxide nanoparticles (ZnO) and Equisetum arvense (EA) herbal extract for potential application as antibacterial and wound healing scaffolds. Full characterization was carried out for fabricated scaffolds before in‐vitro assessments. FTIR spectroscopy and SEM images verified the successful substitution of nanofibers with EA and ZnO. These substitutions increased the hydrophilicity compared to the PCL scaffold. According to the results, the PCL/ZnO/EA fabricated scaffold was hemocompatible and non‐cytotoxic, in addition to allowing proper cell attachment. Effective antibacterial efficiency against Gram‐positive and Gram‐negative bacteria was also observed in this sample. Finally, the in vitro wound healing assay indicated that the addition of ZnO and EA improves the wound healing capacity of the scaffolds. The results indicate the potential of the developed scaffolds to prevent wound contamination and the complications of chronic infection.Highlights Optimal concentrations of zinc oxide nanoparticles (ZnO) and Equisetum arvense (EA) were incorporated into electrospun polycaprolactone (PCL) nanofibers for potential wound dressing applications. The fabricated nanofibrous wound dressings offer a multitude of structural features in biomaterials. PCL fibers enable the controlled release of both ZnO and EA. The fabricated scaffolds exhibit favorable antibacterial, and antioxidant properties while maintaining biocompatibility and hemocompatibility.

Enhancing polyvinyl alcohol surface properties through pre-drying treatment and modified electrospun polycaprolactone nanofibers

The application of polyvinyl alcohol (PVA) as a biodegradable polymer is restricted by its low water resistance, particularly for the packaging of moisture-sensitive products. In this paper, we report on a surface-modification approach for PVA films using electrospinning of beeswax-modified polycaprolactone (PCL) following a 10 min pre-drying process. The pre-drying process led to physical binding between the hydrophobic PCL/beeswax nanofibers and the hydrophilic PVA substrate while the addition of beeswax to PCL improved its physical properties, leading to larger surface roughness and lower wettability of the PVA film. In particular, by adding a proper amount of beeswax to PCL, a PVA/PCL/beeswax composite film showed high hydrophobicity with a water contact angle of 144.1°, demonstrating a significant improvement in the surface properties compared to the hydrophilic bare PVA film. Moreover, the oxygen permeability of the PVA film decreased from 5.5 to 2.2 cc.m−2.day−1 after electrospinning the PCL/beeswax, which was related to the rougher surface morphology generated by the electrospun nanofibers. Therefore, our cost-effective approach has the potential to modify the physical properties of hydrophilic polymers and to broaden their industrial applications.

Sustainable biomaterials for tissue engineering: electrospun polycaprolactone fibers enriched with freshwater snail calcium carbonate and waste human hair keratin

AbstractThis study focuses on developing a sustainable and biocompatible polycaprolactone (PCL)‐based scaffold for bone tissue engineering through electrospinning, utilizing calcium carbonate (CaCO3) from Pomacea canaliculata shells and keratin from human hair, known for stimulating bone regeneration. The isolated CaCO3 has been identified to demonstrate two polymorphs, vaterite and calcite, as determined by X‐ray diffraction. The isolation of keratin from human hair was confirmed through sodium dodecyl sulfate polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy analysis, revealing the presence of α‐keratin structures around 45–50 kDa and β‐keratin structures around 55–60 kDa. According to scanning electron microscope observations, the addition of keratin to PCL fibers reduced their diameter from 457 ± 345 to 371 ± 103 nm. Further addition of calcium carbonate led to a mean diameter of 258 ± 76 nm. The melting temperature of PCL fibers containing keratin and CaCO3 was determined to be 76.17 °C via differential scanning calorimetry, while thermogravimetric analysis, conducted at temperatures up to 600 °C, revealed a remaining ash content of 9.59%. Calcium phosphate accumulation was observed to initiate on PCL fibers containing keratin and CaCO3 following a 7‐day exposure to simulated body fluid. The fibers exhibit cytocompatibility, showing no toxicity while supporting the growth and proliferation of Saos‐2 osteosarcoma cells. The results suggest that the innovative incorporation of keratin and CaCO3 into PCL nanofibers could serve as a bioactive matrix compared to pure PCL matrices, thereby offering enhanced potential for bone tissue engineering applications. © 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Multi-variate multi-objective optimization of production conditions for electro-spun skin scaffold using RSM and investigation of gamma irradiation effects on the properties of the optimized sample

Developing electro-spun scaffolds with ideal mechanical properties for skin purposes can profit from using the Response Surface Methodology technique to define and optimize the outcome quality and required sterilization for use in vivo. This study investigated the effects of four main independent electrospinning variables for polycaprolactone nanofibers scaffold using multi-variable and multi-objective optimization. It was done to determine significant parameters on responses and find optimal conditions to reach the preferred properties. Young's modulus, elongation-at-break, and tensile strength were the responses. After obtaining appropriate models, the impact share of variables on the responses was determined using Sobol sensitivity analysis. The results showed that flow rate is the most significant parameter of elastic modulus and tensile strength responses, with 76.45 % and 41.27 % impact shares, respectively. The polymer concentration is the following significant parameter on elongation at break, tensile strength and, Young's modulus responses with 64.35 %, 39.485 and, 14.28 % impact share, respectively. Based on the optimized results, a skin scaffold with desired mechanical properties was achieved (under solution concentration of 10 % w/v, flow rate of 2 mL/h, nuzzle-collector distance of 15 cm, and applied voltage of 20 kV). Then it was sterilized with gamma radiation of various doses (25, 40, and 55 kGy) to use in vivo. The SEM analysis indicated no significant change in fibrous morphology due to gamma irradiation at any dosage. FTIR analysis demonstrated the breakup of ester bonds due to gamma irradiation. For samples irradiated by 25 kGy, the crystallinity percentage decreased and chains crosslinking without losing the mechanical stability was dominant. The studies demonstrated that 25 kGy of gamma irradiation could improve the mechanical properties of the optimized PCL skin scaffold, which is very promising for wound healing.

Modified five times simulated body fluid for efficient biomimetic mineralization

Simulated body fluid (SBF) is widely utilized in preclinical research for estimating the mineralization efficacy of biomaterials. Therefore, it is of great significance to construct an efficient and stable SBF mineralization system. The conventional SBF solutions cannot maintain a stable pH value and are prone to precipitate homogeneous calcium salts at the early stages of the biomimetic process because of the release of gaseous CO2. In this study, a simple but efficient five times SBF buffered by 5 % CO2 was developed and demonstrated to achieve excellent mineralized microstructure on a type of polymer-aligned nanofibrous scaffolds, which is strikingly similar to the natural human bone tissue. Scanning electron microscopy and energy-dispersive X-ray examinations indicated the growth of heterogeneous apatite with a high-calcium-to-phosphate ratio on the aligned nanofibers under 5 times SBF buffered by 5 % CO2. Moreover, X-ray diffraction spectroscopy and Fourier transform infrared analyses yielded peaks associated with carbonated hydroxyapatite with less prominent crystallization. In addition, the biomineralized aligned polycaprolactone nanofibers demonstrated excellent cell attachment, alignment, and proliferation characteristics in vitro. Overall, the results of this study showed that 5 × SBFs buffered by 5 % CO2 partial pressure are attractive alternatives for the efficient biomineralization of scaffolds in bone tissue engineering, and could be used as a model for the prediction of the bone-bonding bioactivity of biomaterials.

Electrospun Nanofibers with Pomegranate Peel Extract as a New Concept for Treating Oral Infections.

Pomegranate peel extract is known for its potent antibacterial, antiviral, antioxidant, anti-inflammatory, wound healing, and probiotic properties, leading to its use in treating oral infections. In the first stage of this work, for the first time, using the Design of Experiment (DoE) approach, pomegranate peel extract (70% methanol, temperature 70 °C, and three cycles per 90 min) was optimized and obtained, which showed optimal antioxidant and anti-inflammatory properties. The optimized extract showed antibacterial activity against oral pathogenic bacteria. The second part of this study focused on optimizing an electrospinning process for a combination of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers loaded with the optimized pomegranate peel extract. The characterization of the nanofibers was confirmed by using SEM pictures, XRPD diffractograms, and IR-ATR spectra. The composition of the nanofibers can control the release; in the case of PVP-based nanofibers, immediate release was achieved within 30 min, while in the case of PCL/PVP, controlled release was completed within 24 h. Analysis of the effect of different scaffold compositions of the obtained electrofibers showed that those based on PCL/PVP had better wound healing potential. The proposed strategy to produce electrospun nanofibers with pomegranate peel extract is the first and innovative approach to better use the synergy of biological action of active compounds present in extracts in a patient-friendly pharmaceutical form, beneficial for treating oral infections.