In situ precision electrospinning as an effective delivery technique for cyanoacrylate medical glue with high efficiency and low toxicity

Facile roll-to-roll production of nanoporous fiber coatings for advanced wound care sutures

Theranostic sutures are derived from innovative ideas to enhance wound healing results by adding wound diagnostics and therapeutics to typical sutures by functionalizing them with additional materials. Here, we present a new direct electrospinning method for the fast, continuous, inexpensive, and high-throughput production of versatile nanofibrous-coated suture threads, with precise control over various essential microstructural and physical characteristics. The thickness of the coating layer and the alignment of nanofibers with the thread's direction can be adjusted by the user by varying the spooling speed and the displacement between the spinneret needle and thread. To show the flexibility of our method for a range of different materials selected, gelatin, polycaprolactone, silk fibroin, and PEDOT:PSS (poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)) were the resultant nanofibers characterized by scanning electron microscopy (SEM) imaging and conductivity tests. In a series of in vitro and ex vivo tests (pig skin), sutures were successfully tested for their flexibility and mechanical properties when used as weaving and knotting sutures, and their biocompatibility with a keratinocyte cell line. For temperature-based drug-releasing tests, two fluorescent molecules as drug models with high and low molecular weight, namely fluorescein isothiocyanate-dextran (20 kDa) and rhodamine B (470 Da), were used, and their steady release with incremental increase of temperature to 37 °C over 120 min was seen, which is appropriate for bacterial treatment drugs. Given the advantages of the presented technique, it seems to have promising potential to be used in future medical applications for wound closure and bacterial infection treatment via a temperature-triggered drug release strategy.

A systematic review on green and natural polymeric nanofibers for biomedical applications

Electrospinning is the simplest technique to produce ultrathin nanofibers, which enables the use of nanotechnology in various applications. Nanofibrous materials produced through electrospinning have garnered significant attention in biomedical applications due to their unique properties and versatile potential. In recent years, there has been a growing emphasis on incorporating sustainability principles into material design and production. However, electrospun nanofibers, owing to their reliance on solvents associated with significant drawbacks like toxicity, flammability, and disposal challenges, frequently fall short of meeting environmentally friendly standards. Due to the limited solvent choices and heightened concerns for safety and hygiene in modern living, it becomes imperative to carefully assess the implications of employing electrospun nanofibers in diverse applications and consumer products. This systematic review aims to comprehensively assess the current state of research and development in the field of "green and natural" electrospun polymer nanofibers as well as more fascinating and eco-friendly commercial techniques, solvent preferences, and other green routes that respect social and legal restrictions tailored for biomedical applications. We explore the utilization of biocompatible and biodegradable polymers sourced from renewable feedstocks, eco-friendly processing techniques, and the evaluation of environmental impacts. Our review highlights the potential of green and natural electrospun nanofibers to address sustainability concerns while meeting the demanding requirements of various biomedical applications, including tissue engineering, drug delivery, wound healing, and diagnostic platforms. We analyze the advantages, challenges, and future prospects of these materials, offering insights into the evolving landscape of environmentally responsible nanofiber technology in the biomedical field.

Overview of Tissue Engineering and Drug Delivery Applications of Reactive Electrospinning and Crosslinking Techniques of Polymeric Nanofibers with Highlights on Their Biocompatibility Testing and Regulatory Aspects

Traditional electrospinning is a promising technique for fabricating nanofibers for tissue engineering and drug delivery applications. The method is highly efficient in producing nanofibers with morphology and porosity similar to the extracellular matrix. Nonetheless, and in many instances, the process has faced several limitations, including weak mechanical strength, large diameter distributions, and scaling-up difficulties of its fabricated electrospun nanofibers. The constraints of the polymer solution's intrinsic properties are primarily responsible for these limitations. Reactive electrospinning constitutes a novel and modified electrospinning techniques developed to overcome those challenges and improve the properties of the fabricated fibers intended for various biomedical applications. This review mainly addresses reactive electrospinning techniques, a relatively new approach for making in situ or post-crosslinked nanofibers. It provides an overview of and discusses the recent literature about chemical and photoreactive electrospinning, their various techniques, their biomedical applications, and FDA regulatory aspects related to their approval and marketing. Another aspect highlighted in this review is the use of crosslinking and reactive electrospinning techniques to enhance the fabricated nanofibers' physicochemical and mechanical properties and make them more biocompatible and tailored for advanced intelligent drug delivery and tissue engineering applications.

Clinical effect analysis of using medical glue versus conventional suturing to treat dog bite in children's maxillofacial region after negative pressure sealing drainage: A randomized trial

BACKGROUND

To compare the clinical effectiveness of applying medical glue versus conventional suturing after primary suturing and continuous vacuum sealing drainage (VSD) technology in the treatment of facial wounds caused by dog bites in children's maxillofacial region, with respect to operation time, wound infection rate, treatment effect, and patient satisfaction.

METHODS

From May 2020 to July 2022, 68 children with a dog bite in the maxillofacial region were randomly divided into medical glue and conventional suturing groups. The patients in both groups were treated with conventional debridement, tetanus and/or rabies immunization, and antibiotic therapy. The medical glue group was treated with VSD after the first-stage of the loose suture of the wound. After 5 days, the suture was removed, and the wound was tightly bonded with medical glue again. The conventional suturing group was treated with VSD after the first-stage of loose suture of the wound. The primary outcomes were the operation time and satisfaction of the 2 groups, and the secondary outcomes was the wound infection rate.

RESULTS

The operation time of the medical glue group was significantly lower than that of the conventional suturing group. However, there was no significant difference between the 2 groups in the wound infection rate. Still, the patient satisfaction was significantly better in the medical glue group than the conventional suturing group with statistically significant difference (P < .05).

CONCLUSION

In conclusion, applying medical glue after using negative pressure sealing drainage in treating maxillofacial dog bites can reduce surgeons work intensity, lessen children's pain, and improve the clinical treatment effect.

Minimally invasive bioprinting for in situ liver regeneration

In situ bioprinting is promising for developing scaffolds directly on defect models in operating rooms, which provides a new strategy for in situ tissue regeneration. However, due to the limitation of existing in situ biofabrication technologies including printing depth and suitable bioinks, bioprinting scaffolds in deep dermal or extremity injuries remains a grand challenge. Here, we present an in vivo scaffold fabrication approach by minimally invasive bioprinting electroactive hydrogel scaffolds to promote in situ tissue regeneration. The minimally invasive bioprinting system consists of a ferromagnetic soft catheter robot for extrusion, a digital laparoscope for in situ monitoring, and a Veress needle for establishing a pneumoperitoneum. After 3D reconstruction of the defects with computed tomography, electroactive hydrogel scaffolds are printed within partial liver resection of live rats, and in situ tissue regeneration is achieved by promoting the proliferation, migration, and differentiation of cells and maintaining liver function in vivo.

Fabrication of Ceftriaxone-Loaded Cellulose Acetate and Polyvinyl Alcohol Nanofibers and Their Antibacterial Evaluation

Nanotechnology provides solutions by combining the fields of textiles and medicine to prevent infectious microbial spread. Our study aimed to evaluate the antimicrobial activity of nanofiber sheets incorporated with a well-known antibiotic, ceftriaxone. It is a third-generation antibiotic that belongs to the cephalosporin group. Different percentages (0, 5%, 10%, 15%, and 20%; based on polymer wt%) of ceftriaxone were incorporated with a polymer such as polyvinyl alcohol (PVA) via electrospinning to fabricate nanofiber sheets. The Kirby-Bauer method was used to evaluate the antimicrobial susceptibility of the nanofiber sheets using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). For the characterization of the nanofiber sheets incorporated with the drug, several techniques were used, such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Our results showed that the nanofiber sheets containing ceftriaxone had potential inhibitory activity against E. coli and S. aureus as they had inhibition zones of approximately 20–25 mm on Mueller-Hinton-agar-containing plates. In conclusion, our nanofiber sheets fabricated with ceftriaxone have potential inhibitory effects against bacteria and can be used as a dressing to treat wounds in hospitals and for other biomedical applications.

Synthesis of polyacrylonitrile/polytetrahydropyrimidine (PAN/PTHP) nanofibers with enhanced antibacterial and anti-viral activities for personal protective equipment

Emerging infectious diseases caused by the spread of bacteria and viruses are a major burden on global economic development and public health. At present, most personal protective equipment has weak antibacterial and anti-viral properties. The PAN/PTHP nanofibers reported in this article provide a new method for the development of personal protective equipment. In this study, a mixture of PTHP and PAN was prepared into PAN/PTHP nanofibers with high-efficiency and long-lasting antibacterial effects (>99.999%) through the electrospinning process. Live/dead staining and cell proliferation experiments showed that the preparation of PAN/PTHP nanofibers has good cell compatibility. In addition, PAN/PTHP nanofibers show obvious destructive effects on lentiviruses. Based on these characteristics, PAN/PTHP nanofibers were applied to facial masks, which can be used as the inflatable biocidal layer of facial masks and have an excellent interception effect on particles in the air. The successful synthesis of these fascinating materials may provide new insights for the development of new protective materials.

A low-swelling and toughened adhesive hydrogel with anti-microbial and hemostatic capacities for wound healing

Hydrogel-based wound dressings with tissue adhesion abilities are widely used for wound closure. However, currently developed hydrogel adhesives are still poor at continuing to seal wounds while bleeding is ongoing. Herein, we demonstrate an antibacterial and hemostatic hydrogel adhesive with low-swelling properties and toughness for wound healing. The hydrogel was composed of Pluronic F127 diacrylate, quaternized chitosan diacrylate, silk fibroin, and tannic acid, and it was not only able to maintain good tissue adhesion abilities in a moist environment but it also showed guaranteed tissue adhesion and mechanical strength after absorbing water due to its low-swelling and toughness properties. Furthermore, in vitro and in vivo tests demonstrated that the hydrogel also had antibacterial, antioxidant, and hemostatic properties, which could promote tissue regeneration. All these findings demonstrate that this hydrogel with multifunctional properties is a promising material for clinical wound healing applications.

Electrospinning of cyanoacrylate tissue adhesives for human dural repair in endonasal surgery

Cerebral spinal fluid (CSF) leakage is a major postoperative complication requiring surgical intervention, resulting in prolonged healing and higher costs. Biocompatible polymers, such as cyanoacrylates, are currently used as tissue adhesives for closing surgical defects and incisions. Coupling these polymers with nanofiber technology shows promising results for generating nanofibers used in wound care, tissue engineering, and drug delivery. Fiber membranes formed by electrospinning of n-octyl-2-cyanoacrylate (NOCA) are investigated for in situ dural closures after neurosurgery to improve the quality of the closure and prevent post-surgical CSF leaks. Electrospun NOCA fiber membranes showed significantly higher sealing capabilities of defects in human dura, with an average burst pressure of 149 mmHg, compared with that of an FDA-approved common dural sealant that had an average burst pressure of 37 mmHg. In this study, microfabrication of NOCA fibers demonstrates a promising technique for dural repairs.

Electrospun meshes of poly (n-butyl cyanoacrylate) and their potential applications for drug delivery and tissue engineering

The aim of the present work was to develop novel meshes of poly (n-butyl cyanoacrylate) (PBCA) nanofibers for potential applications in drug delivery and tissue engineering taking into account the successful application of PBCA in other medical uses. Electrospinning was applied to solutions of PBCA, 10³ and 10⁶ Da. 5-fluorouracil was chosen as model drug for the delivery study because of its effectiveness against cancer, while human gingival fibroblasts (HFIB-G) to confirm the biocompatibility of drug-free PBCA meshes and their potential for tissue engineering. PBCA was able to be electrospun in a wide range of molecular weights, producing fibers free of defects with diameters between 380 nm and 6 μm. Meshes of PBCA (10⁵-10⁶ Da) showed high flexibility with Younǵs modulus and maximal tension values in the range of 0.3-1.6 MPa and 0.03-0.13 MPa respectively. Results from the drug delivery study suggested that 5-fluorouracil was homogeneously loaded into PBCA meshes. Its release was extremely slow, initially 20% in 7 days and the rest gradually (until 96 days) in physiological medium at 37 °C. HFIB-G were well attached and proliferated over PBCA nanofibers during 23 days. Results suggested that PBCA meshes serve as excellent frameworks for cell adhesion/proliferation, and for drug delivery extended periods.

In-situ Electrospinning for Intestinal Hemostasis

INTRODUCTION

During routine surgery, rapid hemostasis, especially the rapid hemostasis of internal organs, is very important. The emergence of in-situ electrospinning technology has fundamentally solved this problem. It exhibits a high speed of hemostasis, and no bleeding occurs after surgery. Thus, it is of great significance. The use of sutures in some human organs, such as the intestines and bladder, is inadequate because fluid leakage occurs due to the presence of pinholes.

METHODS

Three types of large intestine wounds with an opening of about 1 cm were investigated. They were untreated, treated by needle and threaded, and treated by hand-held electrospinning, respectively.

RESULTS

The results show that hand-held electrospinning technique effectively prevented the exudation of fluids in the intestinal tract. The average diameter of the nanofibrous membrane was about 0.5 μm with hole of several micrometers. It can be elongated 90% without breakage. The hand-held electrospinning device could be used with nitrile gloves, preventing the risk of infection caused by exposed hands.

DISCUSSION

This work can provide a reference for future animal experiments and clinical experiments. However, safety should be investigated before application.

In situ Enabling Approaches for Tissue Regeneration: Current Challenges and New Developments

In situ tissue regeneration can be defined as the implantation of tissue-specific biomaterials (by itself or in combination with cells and/or biomolecules) at the tissue defect, taking advantage of the surrounding microenvironment as a natural bioreactor. Up to now, the structures used were based on particles or gels. However, with the technological progress, the materials' manipulation and processing has become possible, mimicking the damaged tissue directly at the defect site. This paper presents a comprehensive review of current and advanced in situ strategies for tissue regeneration. Recent advances to put in practice the in situ regeneration concept have been mainly focused on bioinks and bioprinting techniques rather than the combination of different technologies to make the real in situ regeneration. The limitation of conventional approaches (e.g., stem cell recruitment) and their poor ability to mimic native tissue are discussed. Moreover, the way of advanced strategies such as 3D/4D bioprinting and hybrid approaches may contribute to overcome the limitations of conventional strategies are highlighted. Finally, the future trends and main research challenges of in situ enabling approaches are discussed considering in vitro and in vivo evidence.

In situ Enabling Approaches for Tissue Regeneration: Current Challenges and New Developments

In situ tissue regeneration can be defined as the implantation of tissue-specific biomaterials (by itself or in combination with cells and/or biomolecules) at the tissue defect, taking advantage of the surrounding microenvironment as a natural bioreactor. Up to now, the structures used were based on particles or gels. However, with the technological progress, the materials' manipulation and processing has become possible, mimicking the damaged tissue directly at the defect site. This paper presents a comprehensive review of current and advanced in situ strategies for tissue regeneration. Recent advances to put in practice the in situ regeneration concept have been mainly focused on bioinks and bioprinting techniques rather than the combination of different technologies to make the real in situ regeneration. The limitation of conventional approaches (e.g., stem cell recruitment) and their poor ability to mimic native tissue are discussed. Moreover, the way of advanced strategies such as 3D/4D bioprinting and hybrid approaches may contribute to overcome the limitations of conventional strategies are highlighted. Finally, the future trends and main research challenges of in situ enabling approaches are discussed considering in vitro and in vivo evidence.

Plasticised Regenerated Silk/Gold Nanorods Hybrids as Sealant and Bio-Piezoelectric Materials

Manual and mechanical suturing are currently the gold standard for bowel anastomosis. If tissue approximation fails, anastomotic leaks occur. Anastomotic leaks may have catastrophic consequences. The development of a fully absorbable, biocompatible sealant material based on a bio-ink silk fibroin can reduce the chance of anastomotic leaks. We have produced a Ca-modified plasticised regenerated silk (RS) with gold nanorods sealant. This sealant was applied to anastomosed porcine intestine. Water absorption from wet tissue substrate applied compressive strains on hybrid RS films. This compression results in a sealant effect on anastomosis. The increased toughness of the hybrid plasticised RS resulted in the designing of a bio-film with superior elongation at break (i.e., ≈200%) and bursting pressure. We have also reported structure-dependent piezoelectricity of the RS film that shows a piezoelectric effect out of the plane. We hope that in the future, bowel anastomosis can be simplified by providing a multifunctional bio-film that makes feasible the mechanical tissue joint without the need for specific tools and could be used in piezoelectric sealant heads.

Recent Advances in Hemostasis at the Nanoscale

Rapid and effective hemostatic materials have received wide attention not only in the battlefield but also in hospitals and clinics. Traditional hemostasis relies on materials with little designability which has many limitations. Nanohemostasis has been proposed since the use of peptides in hemostasis. Nanomaterials exhibit excellent adhesion, versatility, and designability compared to traditional materials, laying a good foundation for future hemostatic materials. This review first summarizes current hemostatic methods and materials, and then introduces several cutting-edge designs and applications of nanohemostatic materials such as polypeptide assembly, electrospinning of cyanoacrylate, and nanochitosan. Particularly, their advantages and working mechanisms are introduced. Finally, the challenges and prospects of nanohemostasis are discussed.

Advances in portable electrospinning devices for in situ delivery of personalized wound care

Electrospinning and electrospun fibrous assemblies have attracted interest in a variety of biomedical fields including woundcare, tissue engineering and drug delivery, due to the large surface-area-to-volume ratio and high porosity of nanofibrous webs. Normally, wound dressings are manufactured well before the point of care, and then packaged and distributed for use at a later stage. More recently, in situ electrospinning of fibers directly onto wound sites has been proposed as a route to personalized wound dressing manufacture, tailored to the needs of individual patients. Practically, in situ deposition of nanofibers on to a wound could be envisaged using a portable or hand-held electrospinning device that is safe and easy to operate. This review focuses on recent advances in portable electrospinning technology and potential applications in woundcare and regenerative medicine. The main research challenges and future trends are also considered.

Light-Activated Tissue-Integrating Sutures as Surgical Nanodevices

Sutures are typically the primary means of soft tissue repair in surgery and trauma. Despite their widespread use, sutures do not result in immediate sealing of approximated tissues, which can result in bacterial infection and leakage. Nonabsorbable sutures and staples can be traumatic to tissue, and the trauma can be exacerbated by their subsequent removal. Use of cyanoacrylate glues is limited because of their brittleness and toxicity. In this work, laser-activated tissue-integrating sutures (LATIS) are described as novel nanodevices for soft tissue approximation and repair. Incorporation of gold nanorods within fibers generated from collagen result in LATIS fibers which demonstrate robust photothermal responses following irradiation with near infrared laser light. Compared to conventional sutures, LATIS fibers result in greater biomechanical recovery of incised skin in a mouse model of skin closure after spine surgeries. Histopathology analyses show improved repair of the epidermal gap in skin, which indicate faster tissue recovery using LATIS. The studies indicate that LATIS-facilitated approximation of skin in live mice synergizes the benefits of conventional suturing and laser-activated tissue integration, resulting in new approaches for faster sealing, tissue repair, and healing.

Poly(propylene fumarate)-based materials: Synthesis, functionalization, properties, device fabrication and biomedical applications

Poly(propylene fumarate) (PPF) is a biodegradable polymer that has been investigated extensively over the last three decades. It has led many scientists to synthesize and fabricate a variety of PPF-based materials for biomedical applications due to its controllable mechanical properties, tunable degradation and biocompatibility. This review provides a comprehensive overview of the progress made in improving PPF synthesis, resin formulation, crosslinking, device fabrication and post polymerization modification. Further, we highlight the influence of these parameters on biodegradation, biocompatibility, and their use in a number of regenerative medicine applications, especially bone tissue engineering. In particular, the use of 3D printing techniques for the fabrication of PPF-based scaffolds is extensively reviewed. The recent invention of a ring-opening polymerization method affords precise control of PPF molecular mass, molecular mass distribution (Ɖ_M) and viscosity. Low Ɖ_M facilitates time-certain resorption of 3D printed structures. Novel post-polymerization and post-printing functionalization methods have accelerated the expansion of biomedical applications that utilize PPF-based materials. Finally, we shed light on evolving uses of PPF-based materials for orthopedics/bone tissue engineering and other biomedical applications, including its use as a hydrogel for bioprinting.

Efficient Synthesis of PVDF/PI Side-by-Side Bicomponent Nanofiber Membrane with Enhanced Mechanical Strength and Good Thermal Stability

Bicomponent composite fibers, due to their unique versatility, have attracted great attention in many fields, such as filtration, energy, and bioengineering. Herein, we efficiently fabricated polyvinylidene fluoride/polyimide (PVDF/PI) side-by-side bicomponent nanofibers based on electrospinning, which resulted in the synergism between PVDF and PI, and eventually obtained the effect of 1 + 1 > 2. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphology and chemical structure of nanofibers, indicating that a large number of side-by-side nanofibers were successfully prepared. Further, the thermal stability, mechanical strength, and filtration properties of PVDF/PI were carefully investigated. The results revealed that the bicomponent nanofibers possessed both good mechanical strength and remarkable thermal stability. Moreover, the mechanical properties of PVDF/ PI were strengthened by more than twice after the heat treatment (7.28 MPa at 25 °C, 15.49 MPa at 230 °C). Simultaneously, after the heat treatment at 230 °C for 30 min, the filtration efficiency of PVDF/PI membrane was maintained at about 95.45 ± 1.09%, and the pressure drop was relatively low. Therefore, the prepared PVDF/PI side-by-side bicomponent nanofibers have a favorable prospect of application in the field of medium- and high-temperature filtration, which further expands the application range of electrospun fiber membranes.

Rapid Soft Tissue Approximation and Repair using Laser-activated Silk Nanosealants

Tissue approximation and repair have been conventionally performed with sutures and staples, but these means are inherently traumatic. Tissue approximation using laser-responsive nanomaterials can lead to rapid tissue sealing and repair, and is an attractive alternative to existing clinical methods. Here, we demonstrate the use of laser-activated nanosealants (LANS) with gold nanorods (GNRs) embedded in silk fibroin polypeptide matrices. The adaptability of LANS for sealing soft tissues is demonstrated using two different modalities: insoluble thin films for internal, intestinal tissue repair, and semi-soluble pastes for external repair, shown by skin repair in live mice. Laser repaired intestinal tissue held over seven times more fluid pressure than sutured intestine and also prevented bacterial leakage. Skin incisions in mice closed using LANS' showed indication of increased mechanical strength and faster repair compared to suturing. Laser-activated silk-GNR nanosealants rapidly seal soft-tissue tears and show high promise for tissue approximation and repair in trauma and routine surgery.

Electric Field-Assisted In Situ Precise Deposition of Electrospun γ-Fe2O3/Polyurethane Nanofibers for Magnetic Hyperthermia

A facial electrospinning method of in situ precise fabricating magnetic fibrous membrane composed of polyurethane (PU) nanofibers decorated with superparamagnetic γ-Fe2O3 nanoparticles with simultaneous heat generation in response to alternating magnetic field (AMF) is reported. In this method, a conical aluminum auxiliary electrode is used to regulate the electrostatic field and affect the process of electrospinning for the in situ rapid and precise deposition of electrospun γ-Fe2O3/PU fibers. The auxiliary conical electrode can extend the jet stabilization zone of the precursor solution four times longer than that of without auxiliary electrode, which can achieve the precise control of the fiber deposition area. Moreover, the electrospun composite fibrous membranes show a rapid temperature increase from room temperature to 43 °C in 70 s under the AMF, which exhibits faster heating rate and higher heating temperature compared to the samples fabricated without the assist of the auxiliary electrode. The present results demonstrate that the in situ precise electrospinning with the help of an auxiliary conical electrode has the potential as a manipulative method for preparing magnetic composite fibers as well as magnetic hyperthermia of cancer therapy.

Solvent-free two-component electrospinning of ultrafine polymer fibers

A new type of solvent-free electrospinning technique was developed to fabricate micro-fibers.

Small Molecular TGF-β1-Inhibitor-Loaded Electrospun Fibrous Scaffolds for Preventing Hypertrophic Scars

Hypertrophic scarring (HS) is a disorder that occurs during wound healing and seriously depresses the quality of human life. Scar-inhibiting scaffolds, though bringing promise to HS prevention, face problems such as the incompatibility of the scaffold materials and the instability of bioactive molecules. Herein, we present a TGF-β1-inhibitor-doped poly(ε-caprolactone) (PCL)/gelatin (PG) coelectrospun nanofibrous scaffold (PGT) for HS prevention during wound healing. The appropriate ratio of PCL to gelatin can avoid individual defects of the two materials and achieve an optimized mechanical property and biocompatibility. The TGF-β1 inhibitor (SB-525334) is a small molecule and is highly stable during electrospinning and drug release processes. The PGT effectively inhibits fibroblast (the major cell type contributing to scar formation) proliferation in vitro and successfully prevents HS formation during the healing of full-thickness model wounds on rabbit ear. Our strategy offers an excellent solution for potential large-scale production of scaffolds for clinical HS prevention.

Engineering a sprayable and elastic hydrogel adhesive with antimicrobial properties for wound healing

Hydrogel-based bioadhesives have emerged as alternatives for sutureless wound closure, since they can mimic the composition and physicochemical properties of the extracellular matrix. However, they are often associated with poor mechanical properties, low adhesion to native tissues, and lack of antimicrobial properties. Herein, a new sprayable, elastic, and biocompatible composite hydrogel, with broad-spectrum antimicrobial activity, for the treatment of chronic wounds is reported. The composite hydrogels were engineered using two ECM-derived biopolymers, gelatin methacryloyl (GelMA) and methacryloyl-substituted recombinant human tropoelastin (MeTro). MeTro/GelMA composite hydrogel adhesives were formed via visible light-induced crosslinking. Additionally, the antimicrobial peptide Tet213 was conjugated to the hydrogels, instilling antimicrobial activity against Gram (+) and (-) bacteria. The physical properties (e.g. porosity, degradability, swellability, mechanical, and adhesive properties) of the engineered hydrogel could be fine-tuned by varying the ratio of MeTro/GelMA and the final polymer concentration. The hydrogels supported in vitro mammalian cellular growth in both two-dimensional and three dimensional cultures. The subcutaneous implantation of the hydrogels in rats confirmed their biocompatibility and biodegradation in vivo. The engineered MeTro/GelMA-Tet213 hydrogels can be used for sutureless wound closure strategies to prevent infection and promote healing of chronic wounds.

Chitosan nanostructures by in situ electrospinning for high-efficiency PM2.5 capture

Nanofiber-based air filters and electrostatic precipitation have stimulated considerable interest because of their high-efficiency for PM2.5 capture. In this paper, we introduce a new method of in situ electrospinning (e-spinning) of nanostructures into a polluted enclosed space to efficiently clean the air. From the comparisons of different polymer precursors and different PM2.5 capture techniques, it can be seen that in situ e-spinning of chitosan aqueous solution into the air exhibits the best PM2.5 capture efficiency, which may be attributed to the stronger polarity of chitosan and the synergistic effect of the strong electrostatic adsorption and surface adhesion of the electrospun (e-spun) nanofibers. A removal rate as high as 3.7 μg m^-3 s^-1 was obtained using this technology with a high efficiency of more than 95% PM2.5 capture. The results obtained from a field test in a smoking room (∼5 × 6 × 3 m³) are still in great agreement with those obtained in an experimental box (∼25 × 30 × 35 cm³). More importantly, chitosan is non-toxic and biodegradable, and is harmless to human health when used as a precursor for in situ e-spinning for PM2.5 capture.

Solvent-free electrospinning: opportunities and challenges

Electrospinning (e-spinning) has attracted tremendous attention because this technology provides a simple and versatile method for fabricating ultrafine fibers from a rich variety of materials including polymers, composites, and ceramics.

Efficacy and safety of Innoseal for air leak after pulmonary resection: a case-control study

BACKGROUND

Prolonged air leak is one of the most common complications after lung surgery and the cause of prolonged hospital stay frequently associated with major postoperative morbidity and thus responsible for even higher hospital costs. This case-control study was designed to test the sealing efficacy and safety of Enable-Innoseal TP4 in patients undergoing pulmonary resection for lung cancer.

METHODS

This was a case-control trial enrolling patients with primary or single site metastatic lung cancer scheduled for elective anatomic or nonanatomic pulmonary resection presenting intraoperative grade 1 or 2 air leak at water submersion test; the study group population was then matched 1:1 according to surgical procedure, male/female ratio, preoperative FEV1, and age.

RESULTS

In the study population, 21 patients (70.0%) presented intraoperative grade 1 air leak and 9 patients grade 2 (30.0%) air leak; after comparison with the control group, we observed a significant shorter time for chest drain removal in the study population (P = 0.0050), whereas no difference was registered in terms of number of days needing for discharge (P = 0.0762).

CONCLUSIONS

Enable-Innoseal TP4 was effective in treating limited intraoperative air leaks after pulmonary resection and preventing prolonged postoperative air leaks in patients receiving either anatomic or nonanatomic lung resections. Further randomized double-arm studies are required to confirm the efficacy of Enable-Innoseal TP4 demonstrated by this pilot study.

Solvent-free electrospinning of UV curable polymer microfibers

Solvent-free electrospinning UV curable materials into ultrathin fibers under UV light radiation and in atmosphere of N₂or air.

Ecofriendly fabrication of ultrathin colorful fibers via UV-assisted solventless electrospinning

A new technique to fabricate ultrathin colorful fibers has been developed via ultraviolet (UV)-assisted solventless electrospinning.

Recent advances in melt electrospinning

With the emergence of one-dimensional (1D) functional nanomaterials and their promising applications, electrospinning (e-spinning) technology and electrospun (e-spun) ultrathin fibers have been widely explored.

Simple piezoelectric ceramic generator-based electrospinning apparatus

A new simple e-spinning setup using a piezoelectric ceramic (PZT) generator as high voltage supply was designed and its performance on electrospinning several polymers was investigated.