Preparation of poly(lactic acid)/graphene oxide nanofiber membranes with different structures by electrospinning for drug delivery

Diagnostic Accuracy of Toluidine Blue Electrospun in Detecting Oral Potentially Malignant Disorders

OBJECTIVE

Oral potentially malignant disorders (OPMDs) with epithelial dysplasia can progress to oral squamous cell carcinoma (OSCC). Toluidine blue (TB) has been used in oral screening with various methods. This study aimed to evaluate the sensitivity and specificity of TB-containing electrospun fibers in detecting OPMDs with epithelial dysplasia compared to histopathology.

METHODS

The concentrations of polyvinylpyrrolidone (PVP) and TB were optimized for fiber diameter and puncture strength using the design of experiments method with a central composite design. These optimized fibers were tested on 36 suspected OPMD lesions in 30 patients, followed by a biopsy for histopathological examination.

RESULTS

The quadratic and two-factor interaction models described the relationship between TB and PVP concentrations and fiber characteristics. The TB-containing electrospun fibers had 77.3% sensitivity and 35.7% specificity in detecting OPMDs with epithelial dysplasia.

CONCLUSION

The TB-containing electrospun fibers offer advantages such as easy application, cost-effectiveness, and enhanced sensitivity in identifying OPMDs with epithelial dysplasia. However, their diagnostic accuracy is insufficient as a standalone diagnostic method, and they should be considered an adjunctive tool for detecting dysplastic changes in the oral epithelium.

TRIAL REGISTRATION

Thailand Clinical Trials Registry: TCTR20240429002.

Ascorbyl palmitate nanofiber-reinforced hydrogels for drug delivery in soft issues

Nanofiber-based hydrogel delivery systems have recently shown great potential in biomedical applications, specifically due to their high surface-to-volume ratio of ultra-fine nanofibers and their ability to carry low solubility drugs. Herein, we introduce a visible light-triggered in situ-gelling drug vehicle (GAP Gel) composed of ascorbyl palmitate (AP) nanofibers and gelatin methacryloyl polymer. AP nanofibers form self-assembled structures through intermolecular interactions with a hydrophobic drug-loading core. We demonstrate that the hydrophilic periphery of AP nanofibers allows them to interact with other hydrophilic molecules via hydrogen bonds. The presence of AP nanofibers significantly enhances the viscoelasticity of GAP Gel in a concentration-dependent manner. Further, GAP Gel shows in vitro biocompatibility and sustained drug delivery efficacy when loaded with a hydrophobic antibiotic. Likewise, GAP Gel shows excellent in vivo biocompatibility when implanted in immunocompetent mice in various forms. Lastly, GAP Gels maintain cell viability when cultured in a 3D-environment over 7 days, establishing it as a promising and versatile hydrogel platform for the delivery of biotherapeutics.

Preparation Method and Application of Porous Poly(lactic acid) Membranes: A Review

Porous membrane technology has garnered significant attention in the fields of separation and biology due to its remarkable contributions to green chemistry and sustainable development. The porous membranes fabricated from polylactic acid (PLA) possess numerous advantages, including a low relative density, a high specific surface area, biodegradability, and excellent biocompatibility. As a result, they exhibit promising prospects for various applications, such as oil-water separation, tissue engineering, and drug release. This paper provides an overview of recent research advancements in the fabrication of PLA membranes using electrospinning, the breath-figure method, and the phase separation method. Firstly, the principles of each method are elucidated from the perspective of pore formation. The correlation between the relevant parameters and pore structure is discussed and summarized, subsequently followed by a comparative analysis of the advantages and limitations of each method. Subsequently, this article presents the diverse applications of porous PLA membranes in tissue engineering, oil-water separation, and other fields. The current challenges faced by these membranes, however, encompass inadequate mechanical strength, limited production efficiency, and the complexity of pore structure control. Suggestions for enhancement, as well as future prospects, are provided accordingly.

Innovative Electrospun Nanofiber Mats Based on Polylactic Acid Composited with Silver Nanoparticles for Medical Applications

Nanofibers are some of the most attractive materials that can modify functionalities for developing new kinds of specific applications and are mainly used as a biomedical material. Herein, we designed and prepared antibacterial nonwoven fiber mats of PLA and PLA composited with Ag nanoparticles by electrospinning. The effects of varying filler contents on their chemical, surface morphology, thermal, water absorbency, and antibacterial properties were investigated using FTIR, SEM/EDS, DSC, swelling ratio, and qualitative and quantitative antibacterial tests. FTIR and EDS spectra indicated that Ag nanoparticles were incorporated in the PLA without chemical bonding. SEM revealed that the average diameter of the PLA nanofibers containing the Ag nanoparticles was more significant than those without those particles. In addition, fiber diameters are proportional to the amount of Ag nanoparticle contents. DSC indicated that the Ag nanoparticles can be incorporated within the PLA matrix without strongly affecting their thermal properties. Moreover, the crystallinity of the composite nonwoven fiber mats was higher than those of fiber mats in the neat PLA. However, TGA revealed that the loaded Ag can improve the thermal stability of the PLA electrospun fiber mats. Accordingly, the antibacterial activities revealed that all the composite nanofiber mats exhibited excellent resistance against S. aureus and E. coli bacterial strains. In addition, in the cell toxicity study, all produced hybrids of nonwoven fiber mats induced a reduction in cell viability for the L929 fibroblast cells. Our results suggest that the designed and prepared nonwoven fiber mats may have good potential for use in the biomedical field, particularly in wound dressing applications.

Nanocomposite of starch, gelatin and itaconic acid-based biodegradable hydrogel and ZnO/cellulose nanofiber: A pH-sensitive sustained drug delivery vehicle

In recent years, hydrogels as drug carriers have been receiving great interest due to their ability to change their behavior in response to one or more external stimuli. However, their initial burst release profile limits their practical applications. Therefore, we prepared a bio-based hydrogel nanocomposite (HNC) using starch, itaconic acid, acrylic acid and gelatin in the presence of CNF/ZnO-based nanohybrid (ZONH) and used it to evaluate the pH-sensitive drug release properties in different pH solutions. The prepared HNCs were analyzed using various spectroscopic and microscopic techniques. The BET analysis and swelling test of the HNC indicated improved porosity and swelling capacity due to the addition of ZONH. From the drug release study, sustained drug release rate was observed at pH 4 than those at pH 7.4 and 9, indicating controlled release as well as pH responsive behavior of the HNC. Moreover, the drug released HNC was reused as a photocatalyst for dye degradation and achieved good degradation (%). The antibacterial activity of ZONH and HNC was observed against EC and SA bacterial strains from the antibacterial test. In summary, the prepared HNC can be considered as a potential sustainable DDS for biomedical applications as well as a photocatalyst for dye contaminated water treatment.

Electrospun Nanofibers: Shaping the Future of Controlled and Responsive Drug Delivery

Electrospun nanofibers for drug delivery systems (DDS) introduce a revolutionary means of administering pharmaceuticals, holding promise for both improved drug efficacy and reduced side effects. These biopolymer nanofiber membranes, distinguished by their high surface area-to-volume ratio, biocompatibility, and biodegradability, are ideally suited for pharmaceutical and biomedical applications. One of their standout attributes is the capability to offer the controlled release of the active pharmaceutical ingredient (API), allowing custom-tailored release profiles to address specific diseases and administration routes. Moreover, stimuli-responsive electrospun DDS can adapt to conditions at the drug target, enhancing the precision and selectivity of drug delivery. Such localized API delivery paves the way for superior therapeutic efficiency while diminishing the risk of side effects and systemic toxicity. Electrospun nanofibers can foster better patient compliance and enhanced clinical outcomes by amplifying the therapeutic efficiency of routinely prescribed medications. This review delves into the design principles and techniques central to achieving controlled API release using electrospun membranes. The advanced drug release mechanisms of electrospun DDS highlighted in this review illustrate their versatility and potential to improve the efficacy of medical treatments.

Polymeric Membranes for Biomedical Applications

Polymeric membranes are selective materials used in a wide range of applications that require separation processes, from water filtration and purification to industrial separations. Because of these materials' remarkable properties, namely, selectivity, membranes are also used in a wide range of biomedical applications that require separations. Considering the fact that most organs (apart from the heart and brain) have separation processes associated with the physiological function (kidneys, lungs, intestines, stomach, etc.), technological solutions have been developed to replace the function of these organs with the help of polymer membranes. This review presents the main biomedical applications of polymer membranes, such as hemodialysis (for chronic kidney disease), membrane-based artificial oxygenators (for artificial lung), artificial liver, artificial pancreas, and membranes for osseointegration and drug delivery systems based on membranes.

Preparation and evaluation in vitro and in vivo of pristinamycin enteric-coated granules based on albumin nanoparticles

CONTEXT

The purpose of this study was to prepare enteric-coated particles based on albumin nanoparticles (NPs) using a mixture of PI_A albumin NPs freeze-dried powder (PA-PI_A) and PII_A albumin NPs freeze-dried powder (PA-PII_A) to improve the bioavailability effect of pristinamycin.

OBJECTIVE

This is the first study on the preparation of pristinamycin into enteric-coated granules based on albumin NPs, and our study has effectively improved the bioavailability of pristinamycin and ensured its safety.

METHODS

Pristinamycin albumin enteric-coated granules (PAEGs) were prepared by hybrid wet granulation. The characterizations of albumin NPs were performed by in vitro and in vivo studies of PAEGs. The assays were analyzed using zeta-sizer, transmission electron microscopy, high-performance liquid chromatography, and a fully automated biochemical index analyzer.

RESULTS

The morphology of NPs was close to spherical. PI_A-NPs and PII_A-NPs respectively had a zeta potential of (-24.33 ± 0.75) mV and (+7.30 ± 0.27) mV and mean size of (251.91 ± 19.64) nm and (232.83 ± 22.61) nm. The release of PI_A and PII_A from PAEGs in the artificial gastrointestinal fluid was as high as 58.46% and 87.79%. In the experimental group of oral PAEGs, PI_A and PII_A were AUC_(0-t) (3.68 ± 0.58) mg·L^-1·h^-1 and (2.81 ± 1.06) mg·L^-1·h^-1. The results of aspartate aminotransferase and alanine aminotransferase biochemical indices showed that there was no significant difference between the experimental and normal groups of oral PAEGs.

CONCLUSION

The PAEGs significantly increased the release of PI_A and PII_A in simulated intestinal fluid and improved the bioavailability. The oral administration of PAEGs may not damage the liver of rats. We hope that our study will promote its industrial development or clinical application.

Preparation and Synergistic Effect of Biomimetic Poly(lactic acid)/Graphene Oxide Composite Scaffolds Loaded with Dual Drugs

To promote the bone repair ability of drug-loaded scaffolds, poly(lactic acid) (PLA)/graphene oxide (GO)/Salvianolic acid B (Sal-B)/aspirin (ASA) dual drug-loaded biomimetic composite scaffolds were prepared. The results showed that the addition of these two drugs delayed the gel formation of the composite system, but a biomimetic nanofiber structure could still be obtained by extending the gel time. The addition of Sal-B increased the hydrophilicity of the scaffold, while an increase in ASA reduced the porosity. Dual drug-loaded scaffolds had good haemocompatibility and synergically promoted the proliferation of MC3T3-E1 cells and enhanced alkaline phosphatase activity. Sustained-release experiments of the two drugs showed that the presence of ASA slowed the cumulative release of Sal-B, while Sal-B promoted the release of ASA. Kinetic modeling showed that the release of both drugs conforms to the Korsmeyer-Peppas model, but Sal-B conforms to the Fick diffusion mechanism and ASA follows Fick diffusion and carrier swelling/dissolution.

Sirolimus-exuding core-shell nanofibers as an implantable carrier for breast cancer therapy: preparation, characterization, in vitro cell studies, and in vivo anti-tumor activity

OBJECTIVE

Breast cancer accounts for significant mortality worldwide. Here, we develop a localized, sustained-release delivery system for breast cancer therapy.

METHODS

Sirolimus (SIR) core-shell nanofibers (NFs) are fabricated by coaxial electrospinning with poly(ε-caprolactone) (PCL) for the core and chitosan and PCL for the shell. The NFs were characterized by SEM, AFM, TEM, XRD, FTIR, water uptake, water contact angle, mechanical properties, drug content, and in vitro release. In vitro and in vivo anticancer effects were investigated.

RESULTS

A sustained release behavior is observed during 480 h that is more extended compared to monoaxial NFs. In vitro cytotoxicity and Annexin V/propidium iodide assays indicate that SIR-loaded coaxial NFs are effective in inhibiting proliferation of 4T1 and MCF-7 cells. Implantation of SIR NFs in 4T1 breast tumor-bearing mice inhibits tumor growth significantly compared to free drug. Histopathological examination shows that suppression of tumor growth by SIR NFs is associated with apoptotic cell death. Furthermore, anti-cancer effects are also confirmed by decreased expression levels of Ki-67, MMP-2, and MMP-9. Histological observation of organs, serological analyses, and the lack of body weight changes indicate in vivo safety of SIR NFs.

CONCLUSIONS

Altogether, we show here that incorporation of SIR into core-shell NFs could act as an effective drug release depot and induce a sustained antitumor response.

Graphene Incorporated Electrospun Nanofiber for Electrochemical Sensing and Biomedical Applications: A Critical Review

The extraordinary material graphene arrived in the fields of engineering and science to instigate a material revolution in 2004. Graphene has promptly risen as the super star due to its outstanding properties. Graphene is an allotrope of carbon and is made up of sp²-bonded carbon atoms placed in a two-dimensional honeycomb lattice. Graphite consists of stacked layers of graphene. Due to the distinctive structural features as well as excellent physico-chemical and electrical conductivity, graphene allows remarkable improvement in the performance of electrospun nanofibers (NFs), which results in the enhancement of promising applications in NF-based sensor and biomedical technologies. Electrospinning is an easy, economical, and versatile technology depending on electrostatic repulsion between the surface charges to generate fibers from the extensive list of polymeric and ceramic materials with diameters down to a few nanometers. NFs have emerged as important and attractive platform with outstanding properties for biosensing and biomedical applications, because of their excellent functional features, that include high porosity, high surface area to volume ratio, high catalytic and charge transfer, much better electrical conductivity, controllable nanofiber mat configuration, biocompatibility, and bioresorbability. The inclusion of graphene nanomaterials (GNMs) into NFs is highly desirable. Pre-processing techniques and post-processing techniques to incorporate GNMs into electrospun polymer NFs are precisely discussed. The accomplishment and the utilization of NFs containing GNMs in the electrochemical biosensing pathway for the detection of a broad range biological analytes are discussed. Graphene oxide (GO) has great importance and potential in the biomedical field and can imitate the composition of the extracellular matrix. The oxygen-rich GO is hydrophilic in nature and easily disperses in water, and assists in cell growth, drug delivery, and antimicrobial properties of electrospun nanofiber matrices. NFs containing GO for tissue engineering, drug and gene delivery, wound healing applications, and medical equipment are discussed. NFs containing GO have importance in biomedical applications, which include engineered cardiac patches, instrument coatings, and triboelectric nanogenerators (TENGs) for motion sensing applications. This review deals with graphene-based nanomaterials (GNMs) such as GO incorporated electrospun polymeric NFs for biosensing and biomedical applications, that can bridge the gap between the laboratory facility and industry.

Keratin/Polylactic acid/graphene oxide composite nanofibers for drug delivery

In this work keratin/poly(lactic acid) (PLA) 50/50 wt blend nanofibers with different loadings of graphene-oxide (GO) were prepared by electrospinning and tested as delivery systems of Rhodamine Blue (RhB), selected as a model of a drug. The effect of GO on the electrospinnability and drug release mechanism and kinetics was investigated. Rheological measurements carried out on the blend solutions revealed unsatisfactory compatibility between keratin and PLA under quiet condition. Accordingly, poor interfacial adhesion between the two phases was observed by SEM analysis of a film prepared by solution casting. On the contrary, keratin chains seem to rearrange under the flux conditions of the electrospinning process thus promoting better interfacial interactions between the two polymers, thereby enhancing their miscibility, which resulted in homogeneous and defect-free nanofibers. The loading of GO into the keratin/PLA solution contributes to increase its viscosity, its shear thinning behavior, and its conductivity. Accordingly, thinner and more homogeneous nanofibers resulted from solutions with a relatively high conductivity coupled with a pronounced shear thinning behavior. FTIR and DSC analyses have underlined, that while the PLA/GO interfacial interactions significantly compete with the PLA/keratin ones, there are no significant effects of GO on the structural organization of keratin in blend with the PLA. However, GO offers several advantages from the application point of view by slightly improving the mechanical properties of the electrospun mats and by slowing down the release of the model drug through the reduction of the matrix swelling.

Poly(lactic acid)-Based Electrospun Fibrous Structures for Biomedical Applications

Poly(lactic acid)(PLA) is an aliphatic polyester that can be derived from natural and renewable resources. Owing to favorable features, such as biocompatibility, biodegradability, good thermal and mechanical performance, and processability, PLA has been considered as one of the most promising biopolymers for biomedical applications. Particularly, electrospun PLA nanofibers with distinguishing characteristics, such as similarity to the extracellular matrix, large specific surface area and high porosity with small pore size and tunable mechanical properties for diverse applications, have recently given rise to advanced spillovers in the medical area. A variety of PLA-based nanofibrous structures have been explored for biomedical purposes, such as wound dressing, drug delivery systems, and tissue engineering scaffolds. This review highlights the recent advances in electrospinning of PLA-based structures for biomedical applications. It also gives a comprehensive discussion about the promising approaches suggested for optimizing the electrospun PLA nanofibrous structures towards the design of specific medical devices with appropriate physical, mechanical and biological functions.

Polydopamine-coated nanocomposite theranostic implants for localized chemotherapy and MRI imaging

Sustained and localized delivery of chemotherapeutics in postoperative cancer treatment leads to a radical improvement in prognosis and a much decreased risk of tumor recurrence. In this work, polydopamine (PDA)-coated superparamagnetic iron oxide nanoparticle (SPION)-loaded polycaprolactone and poly (lactic-co-glycolic acid) fibers were developed as a potential implant to ensure safe and sustained release of the chemotherapeutic drug methotrexate (MTX), as well as provide local contrast for magnetic resonance imaging (MRI). Fibres were prepared by co-axial electrospinning and loaded with MTX-layered double hydroxide (LDH) nanocomposites in the core, yielding organic-inorganic hybrids ranging from 1.23 to 1.48 µm in diameter. After surface coating with PDA, SPIONs were subsequently loaded on the fibre surface and found to be evenly distributed, providing high MRI contrast. In vitro drug release studies showed the PDA coated fibres gave sustained release of MTX over 18 days, and the release profile is responsive to conditions representative of the tumor microenvironment such as slightly acidic pH values or elevated concentrations of the reducing agent glutathione (GSH). In vitro studies with Caco-2 and A549 cells showed highly effective killing with the PDA coated formulations, which was further enhanced at higher levels of GSH. The fibres hence have the potential to act as an implantable drug-eluting platform for the sustained release of cytotoxic agents within a tumor site, providing a novel treatment option for post-operative cancer patients.

Biomedical Applications of Electrospun Graphene Oxide

Graphene oxide (GO) has broad potential in the biomedical sector. The oxygen-abundant nature of GO means the material is hydrophilic and readily dispersible in water. GO has also been known to improve cell proliferation, drug loading, and antimicrobial properties of composites. Electrospun composites likewise have great potential for biomedical applications because they are generally biocompatible and bioresorbable, possess low immune rejection risk, and can mimic the structure of the extracellular matrix. In the current review, GO-containing electrospun composites for tissue engineering applications are described in detail. In addition, electrospun GO-containing materials for their use in drug and gene delivery, wound healing, and biomaterials/medical devices have been examined. Good biocompatibility and anionic-exchange properties of GO make it an ideal candidate for drug and gene delivery systems. Drug/gene delivery applications for electrospun GO composites are described with a number of examples. Various systems using electrospun GO-containing therapeutics have been compared for their potential uses in cancer therapy. Micro- to nanosized electrospun fibers for wound healing applications and antimicrobial applications are explained in detail. Applications of various GO-containing electrospun composite materials for medical device applications are listed. It is concluded that the electrospun GO materials will find a broad range of biomedical applications such as cardiac patches, medical device coatings, sensors, and triboelectric nanogenerators for motion sensing and biosensing.

Preparation of carbon nanofibrous mats encapsulating zero-valent Fe nanoparticles as Fe reservoir for removal of organic pollutants

Zero-valent iron nanoparticles (ZVI NPs) display promising potential in the removal of organic pollutants and heavy metal ions for environmental remediation. However, it is crucial to prevent the oxidation of ZVI NP and control the release of Fe ions under storage and working conditions. In this study, ZVI NPs are encapsulated in single-axial and co-axial carbon nanofibers by electrospinning polyacrylonitrile (PAN)/Fe3+ nanofibrous mats with different structures and then annealing the PAN nanofibrous mats in reduction atmosphere. SEM images show that the diameter of the carbon nanofibers is affected by the structure of the nanofibers and the ZVI NPs content after the annealing treatment. The formation of ZVI NPs is confirmed through XPS spectra and HRTEM characterization. The catalytic degradation of organic pollutants by ZVI NPs encapsulated in the carbon nanofibrous mats is evaluated using methylene blue (MB). The results show that the degradation rate of MB is significantly improved when the ZVI NP content encapsulated in the nanofibers increased. MB is completely degraded by the nanofibrous mats with either the single-axial structure or the co-axial structure, but at a higher degradation rate by the single-axial structure than that by the co-axial structure. These results provide alternatives to utilize the carbon nanofibrous mats encapsulating ZVI NPs as Fe reservoir for the removal of organic pollutants in an emergent or long-term situation for environmental remediation.

Preparation and characterisation of a novel polylactic acid/hydroxyapatite/graphene oxide/aspirin drug-loaded biomimetic composite scaffold

The prepared scaffold has good cytocompatibility, hemocompatibility and controlled drug release, and has biomimetic structure and drug loaded function.

Direct incorporation of nano graphene oxide (nGO) into hydrophobic drug crystals for enhanced aqueous dissolution

This paper reports the development of a successful anti-solvent method that incorporates colloidal nano scale graphene oxide (nGO) directly into hydrophobic drug crystals. The nGO dispersed in solution acted as nucleating sites for crystallization and were embedded into the drug crystals without altering its structure or physical properties such as melting point. Several composites of drugs Sulfamethoxazole and Griseofulvin were synthesized with nGO concentration ranging between 0.2 and 1.0 %. The presence of nGO dramatically enhanced the dissolution rate. The time needed to reach a 50 % release (T50) reduced from 42-14 min with the integration of 0.8 % nGO in SMZ, while in GF the reduction was from 44-27 min with 0.5 % nGO. Increased release rates are attributed to the presence of the hydrophilic nGO which hydrogen bond more so with the aqueous mediums. Therefore, the incorporation of nGO into poorly soluble drugs is an effective approach towards drug delivery and bioavailability improvement and opens a new approach to high performance drug delivery.

An Innovative Nanobody-Based Electrochemical Immunosensor Using Decorated Nylon Nanofibers for Point-of-Care Monitoring of Human Exposure to Pyrethroid Insecticides

A novel ultrasensitive nanobody-based electrochemical immunoassay was prepared for assessing human exposure to pyrethroid insecticides. 3-Phenoxybenzoic acid (3-PBA) is a common human urinary metabolite for numerous pyrethroids, which broadly served as a biomarker for following the human exposure to this pesticide group. The 3-PBA detection was via a direct competition for binding to alkaline phosphatase-embedded nanobodies between free 3-PBA and a 3-PBA-bovine serum albumin conjugate covalently immobilized onto citric acid-decorated nylon nanofibers, which were incorporated on a screen-printed electrode (SPE). Electrochemical impedance spectroscopy (EIS) was utilized to support the advantage of the employment of nanofibrous membranes and the success of the immunosensor assembly. The coupling between the nanofiber and nanobody technologies provided an ultrasensitive and selective immunosensor for 3-PBA detection in the range of 0.8 to 1000 pg mL-1 with a detection limit of 0.64 pg mL-1. Moreover, when the test for 3-PBA was applied to real samples, the established immunosensor proved to be a viable alternative to the conventional methods for 3-PBA detection in human urine even without sample cleanup. It showed excellent properties and stability over time.

Electrospun fibers and their application in drug controlled release, biological dressings, tissue repair, and enzyme immobilization

Electrospinning is a method of preparing microfibers or nanofibers by using an electrostatic force to stretch the electrospinning fluid. Electrospinning has gained considerable attention in many fields due to its ability to produce continuous fibers from a variety of polymers and composites in a simple way. Electrospun nanofibers have many merits such as diverse chemical composition, easily adjustable structure, adjustable diameter, high surface area, high porosity, and good pore connectivity, which give them broad application prospects in the biomedical field. This review systematically introduced the factors influencing electrospinning, the types of electrospun fibers, the types of electrospinning, and the detailed applications of electrospun fibers in controlled drug release, biological dressings, tissue repair and enzyme immobilization fields. The latest progress of using electrospun fibers in these fields was summarized, and the main challenges to be solved in electrospinning technology were put forward.

The Process⁻Property⁻Performance Relationship of Medicated Nanoparticles Prepared by Modified Coaxial Electrospraying

In pharmaceutical nanotechnology, the intentional manipulation of working processes to fabricate nanoproducts with suitable properties for achieving the desired functional performances is highly sought after. The following paper aims to detail how a modified coaxial electrospraying has been developed to create ibuprofen-loaded hydroxypropyl methylcellulose nanoparticles for improving the drug dissolution rate. During the working processes, a key parameter, i.e., the spreading angle of atomization region (θ, °), could provide a linkage among the working process, the property of generated nanoparticles and their functional performance. Compared with the applied voltage (V, kV; D = 2713 - 82V with RθV2 = 0.9623), θ could provide a better correlation with the diameter of resultant nanoparticles (D, nm; D = 1096 - 5θ with RDθ2 = 0.9905), suggesting a usefulness of accurately predicting the nanoparticle diameter. The drug released from the electrosprayed nanoparticles involved both erosion and diffusion mechanisms. A univariate quadratic equation between the time of releasing 95% of the loaded drug (t, min) and D (t = 38.7 + 0.097D - 4.838 × 105D2 with a R2 value of 0.9976) suggests that the nanoparticle diameter has a profound influence on the drug release performance. The clear process-property-performance relationship should be useful for optimizing the electrospraying process, and in turn for achieving the desired medicated nanoparticles.

Synthetic Biodegradable Aliphatic Polyester Nanocomposites Reinforced with Nanohydroxyapatite and/or Graphene Oxide for Bone Tissue Engineering Applications

This paper provides review updates on the current development of bionanocomposites with polymeric matrices consisting of synthetic biodegradable aliphatic polyesters reinforced with nanohydroxyaptite (nHA) and/or graphene oxide (GO) nanofillers for bone tissue engineering applications. Biodegradable aliphatic polyesters include poly(lactic acid) (PLA), polycaprolactone (PCL) and copolymers of PLA-PGA (PLGA). Those bionanocomposites have been explored for making 3D porous scaffolds for the repair of bone defects since nHA and GO enhance their bioactivity and biocompatibility by promoting biomineralization, bone cell adhesion, proliferation and differentiation, thus facilitating new bone tissue formation upon implantation. The incorporation of nHA or GO into aliphatic polyester scaffolds also improves their mechanical strength greatly, especially hybrid GO/nHA nanofilllers. Those mechanically strong nanocomposite scaffolds can support and promote cell attachment for tissue growth. Porous scaffolds fabricated from conventional porogen leaching, and thermally induced phase separation have many drawbacks inducing the use of organic solvents, poor control of pore shape and pore interconnectivity, while electrospinning mats exhibit small pores that limit cell infiltration and tissue ingrowth. Recent advancement of 3D additive manufacturing allows the production of aliphatic polyester nanocomposite scaffolds with precisely controlled pore geometries and large pores for the cell attachment, growth, and differentiation in vitro, and the new bone formation in vivo.

Electrospun Polylactic Acid Based Nanofibers for Biomedical Applications

Electrospinning technique has excellent advantages such as tunable functionality, thin fibers with large surface areas, ease of processing and good physical properties. Electrospinning provides wide usage area with these advantages in biomedical applications. Polylactic acid (PLA) is a biodegradable and biocompatible polymer, so it can be used in various biomedical applications. PLA can be easily electrospun from solution by using different kinds of conventional solvents. Electrospun PLA based nanofibers are used in many biomedical applications such as drug delivery, scaffold for tissue engineering, dressings for wound healing, dental applications etc. This review focuses on electrospun PLA based nanofibers used in biomedical applications in recent years. Future perspectives of electrospun PLA based fibers are also discussed in the last part.

A gene-activating skin substitute comprising PLLA/POSS nanofibers and plasmid DNA encoding ANG and bFGF promotes in vivo revascularization and epidermalization

A gene-activated porous nanofibrous scaffold for effectively promoting vascularization, epidermalization and dermal wound healing by sustained release of dual plasmid DNAs.