ZIF-8 induced hydroxyapatite-like crystals enabled superior osteogenic ability of MEW printing PCL scaffolds.

ZIF-8 may experience ion-responsive degradation in ionic solutions, which will change its initial architecture and restrict its direct biological use. Herein, we report an abnormal phenomenon in which ZIF-8 induces large hydroxyapatite-like crystals when soaked directly in simulated body fluid. These crystals grew rapidly continuously for two weeks, with the volume increasing by over 10 folds. According to Zn2+ release and novel XRD diffraction peak presence, ZIF-8 particles can probably show gradual collapse and became congregate through re-nucleation and competitive coordination. The phenomenon could be found on ZIF-8/PCL composite surface and printed ZIF-8/PCL scaffold surface. ZIF-8 enhanced PCL roughness through changing the surface topography, while obviously improving the in-vivo and in-vitro osteoinductivity and biocompatibility. The pro-biomineralization property can make ZIF-8 also applicable in polylactic acid-based biomaterials. In summary, this study demonstrates that ZIF-8 may play the role of a bioactive additive enabling the surface modification of synthetic polymers, indicating that it can be applied in in-situ bone regeneration.

LRG-1 promotes fat graft survival through the RAB31-mediated inhibition of hypoxia-induced apoptosis.

Autologous adipose tissue is an ideal soft tissue filling material, and its biocompatibility is better than that of artificial tissue substitutes, foreign bodies and heterogeneous materials. Although autologous fat transplantation has many advantages, the low retention rate of adipose tissue limits its clinical application. Here, we identified a secretory glycoprotein, leucine-rich-alpha-2-glycoprotein 1 (LRG-1), that could promote fat graft survival through RAB31-mediated inhibition of hypoxia-induced apoptosis. We showed that LRG-1 injection significantly increased the maintenance of fat volume and weight compared with the control. In addition, higher fat integrity, more viable adipocytes and fewer apoptotic cells were observed in the LRG-1-treated groups. Furthermore, we discovered that LRG-1 could reduce the ADSC apoptosis induced by hypoxic conditions. The mechanism underlying the LRG-1-mediated suppression of the ADSC apoptosis induced by hypoxia was mediated by the upregulation of RAB31 expression. Using LRG-1 for fat grafts may prove to be clinically successful for increasing the retention rate of transplanted fat.

Exploring the Circular Polarization Capacity from Chiral Cellulose Nanocrystal Films for a Photo-Controlled Chiral Helix of Supramolecular Polymers.

Circularly polarized light (CPL) is key to asymmetric photochemistry as it could impart the chiral organization information into chemical products. Here, we demonstrate the circular polarization capacity of chiral cellulose nanocrystal (CNC) films to trigger photo-alignment of achiral supramolecular polymers into helical structures. Right-handed transmitted (T-) CPL was generated from self-assembled CNC films, which induced amorphous azobenzene (Azo) supramolecular polymers into chiral structures. The chiral induction effect of T-CPL is enhanced on Azo polymers with longer spacers. The absorptive dissymmetry factor (gabs ) values of liquid-crystal supramolecular polymers can be amplified significantly (over 10 times) after T-CPL irradiation. Moreover, by integrating carbon dots into CNC films, CPL emission with a considerable luminescence dissymmetry factor (glum ) up to -0.66 was achieved, and it could be used for the photo-alignment of Azo polymers with high chiroptical properties. This work provides new insight for the photo modulation of supramolecular polymers by CPL-active materials.

Breast contracture and skin sclerosis following 20 years of polyacrylamide hydrogel migration in a patient with familial vitiligo: a case report.

BACKGROUND: Breast augmentation with polyacrylamide gel (PAAG) injection was approved in China in 1998 and later banned in 2006. The ban ensued numerous complaints from patients such as pain, induration, deformation, infection, displacement, and milk deposition associated with PAAG injection. To date, no study has investigated the long-term effect of PAAG migration on autoimmune diseases. CASE PRESENTATION: We report a rare case of a 49-year-old female patient with familial vitiligo who receiving PAAG injection for breast augmentation. The patient reported to have felt persistent movement of PAAG in her thoracoabdominal area for almost 20 years. Furthermore, the PAAG-induced chronic inflammation that aggravated vitiligo, which in turn promoted skin sclerosis. This damaged the breast contracture, increased chest tightness and induced mild breathing problems. CONCLUSION: Here, we present a rare case in which a patient with a family history of vitiligo experienced long-term complications after receiving PAAG injection for breast augmentation. This case highlights the relationship between vitiligo, migration of PAAG and tissue hardening and skin contraction. LEVEL OF EVIDENCE: Level V.

Reducing Prominent Mandibular Angle Osteotomy Complications: 10-Year Retrospective Review.

BACKGROUND: Several methods are available for mandibular reduction, and each method is characterized by unique limitations and complications. However, only a few studies have systematically analyzed these complications. This study aimed to investigate the effects of the outcome of performing curved mandibular angle ostectomy and outer cortex grinding in 1-stage operation and to examine the causes of different types and characteristics of complications. METHODS: The subjects consisted of 528 patients who were subjected to curved mandibular angle ostectomy and outer cortex grinding in 1-stage operation through an intraoral approach. Surgical complications and related factors were recorded, and the rates of complication according to surgeons were simultaneously evaluated. RESULTS: The esthetic appearance of all of the patients was significantly improved, and they were satisfied with the results of the operation. The complication rate was 5.87%. No serious complications, such as subcondylar fracture, massive bleeding, permanent facial nerve, or asymmetry, occurred. Some complications, including 4 cases of hematoma, 4 cases of severe swelling, 2 cases of infection, and 1 case of sagging face, were detected. The absolute complication rate among faculty members ranged from 3.5% to 11.1%. CONCLUSIONS: Our protocol is an effective method for mandibular angle osteotomy with very few complications. The rate of complications can be effectively reduced, and some serious complications can be avoided because protective measures are improved.

Clinical Outcomes of Digital Three-Dimensional Hydroxyapatite in Repairing Calvarial Defects.

PURPOSE: The objective of this article is to present the long-term outcomes of digital three-dimensional (3D) hydroxyapatite (HA) implants used for calvarial defects. Porous HA provide good results and have many characteristics, making it suitable for calvarial defect reconstruction. However, using HA may be associated with potentially serious complications, including infection and exposure. The authors used digital 3D HA for cranioplasty for many years and accumulated considerable experience from using it. The authors found that digital 3D HA is an effective method for cranioplasty, showing low complication rate. METHODS: A total of 57 patients underwent calvarial defect reconstruction with 3D HA from June 2009 to August 2016. The follow-up period was 1 to 5 years. RESULTS: Most patients (91.2%) were greatly satisfied with the esthetic outcomes of the surgery. The highest rate of complication was seroma (8.8%). Two patients developed postoperative infections (3.5%). One patient with infections was successfully treated with antibiotic therapy. Another patient was required to undergo an extensive surgical debridement followed by delayed autogenous bone reconstruction. One patient suffered from implant exposure. No hematoma, unexpected fractures, asymmetry, and contour or implant abnormalities occurred. CONCLUSIONS: The digital 3D HA implant was highly biocompatible and durable for the reconstruction of calvarial defects. With appropriate treatment, the proposed method was able to achieve a functional and cosmetic reconstruction with lesser complications.

Cranioplasty With Mandibular Outer Cortex Bone Grafts.

BACKGROUND: Autologous bone grafts are still the best materials for calvarial reconstruction. In the past, rib, iliac crest, and cranial bone have been used for the reconstruction of the calvarial defects. However, the use of mandibular outer cortex bone graft in calvarial defects reconstruction is poorly reported in literature. This study focused on using the mandibular outer cortex bone grafts for calvarial defects. METHODS: From October 2004 to July 2016, there were a total of 13 patients in this study who underwent cranioplasty with mandibular outer cortex bone grafts to reconstruction calvarial defects. All the patients were followed up for at least 6 months. RESULTS: The majority of the patients were satisfied with the reconstructive outcome. CONCLUSION: The authors consider the mandibular outer cortex bone graft can achieve excellent esthetic results in selected cranioplasty reconstructions.

Synergistic large segmental bone repair by 3D printed bionic scaffolds and engineered ADSC nanovesicles: Towards an optimized regenerative microenvironment.

Achieving sufficient bone regeneration in large segmental defects is challenging, with the structure of bone repair scaffolds and their loaded bioactive substances crucial for modulating the local osteogenic microenvironment. This study utilized digital laser processing (DLP)-based 3D printing technology to successfully fabricate high-precision methacryloylated polycaprolactone (PCLMA) bionic bone scaffold structures. Adipose-derived stem cell-engineered nanovesicles (ADSC-ENs) were uniformly and stably modified onto the bionic scaffold surface using a perfusion device, constructing a conducive microenvironment for tissue regeneration and long bone defect repair through the scaffold's structural design and the vesicles' biological functions. Scanning electron microscopy (SEM) examination of the scaffold surface confirmed the efficient loading of ADSC-ENs. The material group loaded with vesicles (PCLMA-BAS-ENs) demonstrated good cell compatibility and osteogenic potential when analyzed for the adhesion and osteogenesis of primary rabbit bone marrow mesenchymal stem cells (BMSCs) on the material surface. Tested in a 15 mm critical rabbit radial defect model, the PCLMA-BAS-ENs scaffold facilitated near-complete bone defect repair after 12 weeks. Immunofluorescence and proteomic results indicated that the PCLMA-BAS-ENs scaffold significantly improved the osteogenic microenvironment at the defect site in vivo, promoted angiogenesis, and enhanced the polarization of macrophages towards M2 phenotype, and facilitated the recruitment of BMSCs. Thus, the PCLMA-BAS-ENs scaffold was proven to significantly promote the repair of large segmental bone defects. Overall, this strategy of combining engineered vesicles with highly biomimetic scaffolds to promote large-segment bone tissue regeneration holds great potential in orthopedic and other regenerative medicine applications.

Osteoinductive micro-nano guided bone regeneration membrane for in situ bone defect repair.

BACKGROUND: Biomaterials used in bone tissue engineering must fulfill the requirements of osteoconduction, osteoinduction, and osseointegration. However, biomaterials with good osteoconductive properties face several challenges, including inadequate vascularization, limited osteoinduction and barrier ability, as well as the potential to trigger immune and inflammatory responses. Therefore, there is an urgent need to develop guided bone regeneration membranes as a crucial component of tissue engineering strategies for repairing bone defects. METHODS: The mZIF-8/PLA membrane was prepared using electrospinning technology and simulated body fluid external mineralization method. Its ability to induce biomimetic mineralization was evaluated through TEM, EDS, XRD, FT-IR, zeta potential, and wettability techniques. The biocompatibility, osteoinduction properties, and osteo-immunomodulatory effects of the mZIF-8/PLA membrane were comprehensively evaluated by examining cell behaviors of surface-seeded BMSCs and macrophages, as well as the regulation of cellular genes and protein levels using PCR and WB. In vivo, the mZIF-8/PLA membrane's potential to promote bone regeneration and angiogenesis was assessed through Micro-CT and immunohistochemical staining. RESULTS: The mineralized deposition enhances hydrophilicity and cell compatibility of mZIF-8/PLA membrane. mZIF-8/PLA membrane promotes up-regulation of osteogenesis and angiogenesis related factors in BMSCs. Moreover, it induces the polarization of macrophages towards the M2 phenotype and modulates the local immune microenvironment. After 4-weeks of implantation, the mZIF-8/PLA membrane successfully bridges critical bone defects and almost completely repairs the defect area after 12-weeks, while significantly improving the strength and vascularization of new bone. CONCLUSIONS: The mZIF-8/PLA membrane with dual osteoconductive and immunomodulatory abilities could pave new research paths for bone tissue engineering.

Clay Sculpture-Inspired 3D Printed Microcage Module Using Bioadhesion Assembly for Specific-Shaped Tissue Vascularization and Regeneration.

3D bioprinting techniques have enabled the fabrication of irregular large-sized tissue engineering scaffolds. However, complicated customized designs increase the medical burden. Meanwhile, the integrated printing process hinders the cellular uniform distribution and local angiogenesis. A novel approach is introduced to the construction of sizable tissue engineering grafts by employing hydrogel 3D printing for modular bioadhesion assembly, and a poly (ethylene glycol) diacrylate (PEGDA)-gelatin-dopamine (PGD) hydrogel, photosensitive and adhesive, enabling fine microcage module fabrication via DLP 3D printing is developed. The PGD hydrogel printed micocages are flexible, allowing various shapes and cell/tissue fillings for repairing diverse irregular tissue defects. In vivo experiments demonstrate robust vascularization and superior graft survival in nude mice. This assembly strategy based on scalable 3D printed hydrogel microcage module could simplify the construction of tissue with large volume and complex components, offering promise for diverse large tissue defect repairs.

Reconfigurable Magnetic Liquid Building Blocks for Constructing Artificial Spinal Column Tissues.

All-liquid molding can be used to transform a liquid into free-form solid constructs, while maintaining internal fluidity. Traditional biological scaffolds, such as cured pre-gels, are normally processed in solid state, sacrificing flowability and permeability. However, it is essential to maintain the fluidity of the scaffold to truly mimic the complexity and heterogeneity of natural human tissues. Here, this work molds an aqueous biomaterial ink into liquid building blocks with rigid shapes while preserving internal fluidity. The molded ink blocks for bone-like vertebrae and cartilaginous-intervertebral-disc shapes, are magnetically manipulated to assemble into hierarchical structures as a scaffold for subsequent spinal column tissue growth. It is also possible to join separate ink blocks by interfacial coalescence, different from bridging solid blocks by interfacial fixation. Generally, aqueous biomaterial inks are molded into shapes with high fidelity by the interfacial jamming of alginate surfactants. The molded liquid blocks can be reconfigured using induced magnetic dipoles, that dictated the magnetic assembly behavior of liquid blocks. The implanted spinal column tissue exhibits a biocompatibility based on in vitro seeding and in vivo cultivating results, showing potential physiological function such as bending of the spinal column.

Cellulose nanocrystals-based bio-composite optical materials for reversible colorimetric responsive films and coatings.

Photonic materials with a tunable chiral nematic structure that can selectively reflect light dynamically are valuable for applications in smart responsive materials. Here, we prepared potential photonic composites with a chiral nematic structure by forming cellulose nanocrystals (CNCs) and waterborne polyurethane (WPU) composites with different compositions on different substrates by evaporation-induced self-assembly. With increasing WPU content, the reflected wavelength increased from 400 to 680 nm, which was mainly caused by the increase of the chiral nematic pitch. In addition, the mechanical properties were better for higher WPU content. WPU was sensitive to small amounts of moisture in ethanol owing to the swollen WPU after absorbing water will increase the helical pitch. The reversible red shift induced by moisture was approximately 100 nm. When wood was used as the substrate, the CNCs still self-assembled to form chiral nematic structures and the adhesion forces of the composites to the wood substrate were strong. By using MgCl2 solution as an ink, invisible patterns can be written on the coating, which can be revealed temporarily by ethanol. In addition, the invisible pattern of photonic coating is rewritable. The easily prepared environmentally friendly photonic composite has great potential in sensors, anti-counterfeiting labels and smart decorative coatings.

Pearl-inspired graphene oxide-collagen microgel with multi-layer mineralization through microarray chips for bone defect repair.

Biomineralization of natural polymers in simulated body fluid (SBF) can significantly improve its biocompatibility, osteoconductivity, and osteoinductivity because of the hydroxyapatite (HAp) deposition. Nevertheless, the superficial HAp crystal deposition hamper the deep inorganic ions exchange in porous microgels, thus gradually leading to a nonuniform regeneration effect. Inspired by the pearl forming process, this article uses the microarray chips to fabricate the multi-layer mineralized graphene oxide (GO)-collagen (Col)-hydroxyapatite (HAp) microgel, denoted as MMGCH. These fabricated MMGCH microgels exhibit porous structure and uniform HAp distribution. Furthermore, the suitable microenvironment offered by microgel promotes the time-dependent proliferation and osteogenic differentiation of stem cells, which resulted in upregulated osteogenesis-related genes and proteins, such as alkaline phosphatase, osteocalcin, and collagen-1. Finally, the MMGCH microgels possess favorable bone regeneration capacities both in cranial bone defects and mandibular bone defects via providing a suitable microenvironment for host-derived cells to form new bone tissues. This work presents a biomimetic means aiming to achieve full-thickness and uniform HAp deposition in hydrogel for bone defect repair.

Lipid in Chips: A Brief Review of Liposomes Formation by Microfluidics.

Liposomes are ubiquitous tools in biomedical applications, such as drug delivery, membrane science and artificial cell. Micro- and nanofabrication techniques have revolutionized the preparation of liposomes on the microscale. State-of-the-art liposomal formation on microfluidic chips and its associated applications are introduced in this review. We attempt to provide a reference for liposomal researchers by comparing various microfluidic techniques for liposomes formation.

Graphene Oxide Functionalized Double-Layered Patch with Anti-Adhesion Ability for Abdominal Wall Defects.

BACKGROUND: Effective repair of full-thickness abdominal wall defects requires a patch with sufficient mechanical strength and anti-adhesion characteristics to avoid the formation of hernias and intra-abdominal complications such as intestinal obstruction and fistula. However, patches made from polymers or bio-derived materials may not meet these requirements and lack the bionic characteristics of the abdominal wall. MATERIALS AND METHODS: In this study, we report a consecutive electrospun method for preparing a double-layer structured nanofiber membrane (GO-PCL/CS-PCL) using polycaprolactone (PCL), graphene oxide (GO) and chitosan (CS). To expand the bio-functions (angiogenesis/reducing reactive oxygen species) of the patch (GO-PCL/NAC-CS-PCL), N-acetylcysteine (NAC) was loaded for the repair of full-thickness abdominal wall defects (2×1.5cm) in rat model. RESULTS: The double-layered patch (GO-PCL/NAC-CS-PCL) showed excellent mechanical strength and biocompatibility. After 2 months, rats treated with the patch exhibited the desired repair effect with no hernia formation, less adhesion (adhesion score: 1.50±0.50, P<0.001) and more collagen deposition (percentage of collagen deposition: 34.94%±3.31%, P<0.001). CONCLUSION: The double-layered nanomembranes presented in this study have good anti-hernia and anti-adhesion effects, as well as improve the microenvironment in vivo. It, therefore, holds good prospects for the repair of abdominal wall defects and provides a promising key as a postoperative anti-adhesion agent.

Multi-Layered Polyamide/Collagen Scaffolds with Topical Sustained Release of N-Acetylcysteine for Promoting Wound Healing.

BACKGROUND: Impaired wound healing might be associated with many issues, especially overactive of reactive oxygen species (ROS), deficiency of blood vessels and immature of epidermis. N-acetylcysteine (NAC), as an antioxidant, could solve these problems by inhibiting overreactive of ROS, promoting revascularization and accelerating re-epithelialization. How to deliver NAC in situ with a controllable releasing speed still remain a challenge. MATERIALS AND METHODS: In this study, we combined collagen (Col) with N-acetylcysteine to perform the characteristics of sustained release and chemically crosslinked Col/NAC composite with polyamide (PA) nanofibers to enhance the mechanical property of collagen and fabricated this multi-layered scaffold (PA-Col/NAC scaffold). The physical properties of the scaffolds such as surface characteristics, water absorption and tensile modulus were tested. Meanwhile, the ability to promote wound healing in vitro and in vivo were investigated. RESULTS: These scaffolds were porous and performed great water absorption. The PA-Col/NAC scaffold could sustainably release NAC for at least 14 days. After cell implantation, PA-Col/NAC scaffold showed better cell proliferation and cell migration than the other groups. In vivo, PA-Col/NAC scaffolds could promote wound healing best among all the groups. CONCLUSION: The multi-layered scaffolds could obviously accelerate the process of wound healing and exert better and prolonged effects.

A biocompatible vascularized graphene oxide (GO)-collagen chamber with osteoinductive and anti-fibrosis effects promotes bone regeneration in vivo.

The survival of transplanted cells and tissues in bone regeneration requires a microenvironment with a vibrant vascular network. A tissue engineering chamber can provide this in vivo. However, the commonly used silicone chamber is biologically inert and can cause rejection reactions and fibrous capsule. Studies have revealed that collagen is highly biocompatible and graphene oxide (GO) could regulate osteogenic activity in vivo. Besides, GO can be cross-linked with natural biodegradable polymers to construct scaffolds. Methods: A vascularized GO-collagen chamber model was built by placing vessels traversing through the embedded tissue-engineered grafts (osteogenic-induced bone mesenchymal stem cells -gelatin) in the rat groin area. Osteogenic activity and inflammatory reactions were assessed using different methods including micro-CT scanning, Alizarin red staining, and immunohistochemical staining. Results: After one month, in vivo results showed that bone mineralization and inflammatory responses were significantly pronounced in the silicone model or no chamber (control) groups. Vascular perfusion analysis confirmed that the GO-collagen chamber improved the angiogenic processes. Cells labeled with EdU revealed that the GO-collagen chamber promoted the survival and osteogenic differentiation of bone mesenchymal stem cells. Conclusion: Overall, the novel biocompatible GO-collagen chamber exhibited osteoinductive and anti-fibrosis effects which improved bone regeneration in vivo. It can, therefore, be applied to other fields of regenerative medicine.

Biocompatible graphene oxide-collagen composite aerogel for enhanced stiffness and in situ bone regeneration.

The developing bone graft substitutes have become a promising strategy for repairing large bone loss. Aerogels that made from natural polymers were widely investigated for synthetic bone graft due to their high porosity and great biocompatibility. However, the mechanical properties of natural polymer aerogel are extremely poor for large bone repair. Graphene oxide (GO) is one of the nanomaterials with great mechanical properties as well as biocompatibility, making it a promising component when constructing hybrid aerogels for bone regeneration. In the present study, we have developed a highly porous aerogel consist of GO and type I collagen (COL) using sol-gel process (concentrations of GO: 0%, 0.05%, 0.1%, and 0.2% w/v). Results indicated that GO-COL aerogels were highly porous and hydrophilic. Furthermore, the compressive modulus of GO-COL aerogels was enhanced with the GO concentration increased. For in vitro experiment, 0.1% GO-COL aerogel exhibited better biomineralization rate and cell compatibility than other groups of aerogels. For in vivo study, a better bone repair effect was observed in 0.1% GO-COL aerogels than COL aerogel in rat cranial defect models. This study indicated that 0.1% GO-COL aerogel exhibited good biocompatibility and osteogenic ability in vivo, which make it a promising biocompatible scaffold for bone regeneration and tissue engineering.

Self-Assembled Human Adipose-Derived Stem Cell-Derived Extracellular Vesicle-Functionalized Biotin-Doped Polypyrrole Titanium with Long-Term Stability and Potential Osteoinductive Ability.

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs), containing proteins or microRNAs (miRNAs), possessing various biological activity and low immunogenicity, are considered promising for surface modification of bone grafts. However, the modification efficiency is not satisfied yet, resulting in compromised therapy effects. Here, we report a novel immobilized method by self-assembling biotinylated MSC-EVs onto the surface of biotin-doped polypyrrole titanium (Bio-Ppy-Ti) to improve its biofunctions in vitro and in vivo. Using this method, the amount of human adipose-derived stem cell-EVs (hASC-EVs) anchored onto the Bio-Ppy-Ti surface was 185-fold higher than that of pure Ti after ultrasonic concussion for 30 s and it remained stable on the Bio-Ppy-Ti surface for 14 days at 4 °C. Compared to pristine Ti, EV-Bio-Ppy-Ti exhibited enhanced cell compatibility and osteoinductivity for osteoblasts in vitro and anti-apoptosis ability in the ectopic bone formation mode. Gene chip analysis further demonstrated that several osteoinductive miRNAs were encapsulated in hASC-EVs, which may explain the high bone regeneration ability of EV-Bio-Ppy-Ti. Thus, this MSC-EV biotin-immobilized method appears to be highly efficient and long-term stable for bone graft bioactive modification, demonstrating its potential for clinical metal implants.

Sustained release of N-acetylcysteine by sandwich structured polycaprolactone/collagen scaffolds for wound healing.

PCL (poly-caprolactone) nanofibers have good biocompatibility and high porosity, which are usually utilized for application in wound dressings. However, wound healing could be hindered by the overproduction of reactive oxygen species (ROS) and different factors. Pure nanofibers cannot satisfy these requirements of wound healing. N-acetylcysteine (NAC), as an antioxidant, meets the requirements for wound healing by resisting the overproduction of ROS and by promoting angiogenesis and maturation of the epidermis. In this study, we prepared a sandwich structured PCL-Col/NAC scaffold using the molding method, which consisted of PCL nanofibers at the core and NAC-loaded collagen on both sides. The hydroscopicity and tensile modulus of PCL-Col/NAC scaffolds showed best performance of these properties among groups. Meanwhile, the drug release profiles of PCL-Col/NAC scaffolds were investigated using the HPLC method and the results suggested a sustained drug release of NAC for PCL-Col/NAC scaffolds. In addition, PCL-Col/NAC scaffolds presented better properties than the control groups in cell migration and proliferation. The in vivo wound healing therapy effect was studied using an oval (2 × 1 cm) full-thickness skin defect wound model for SD rats. After 21 days, gross view and histological analysis showed a favorable beneficial therapeutic effect as well as better epidermal maturation compared with the control groups. CD31 immunohistology results revealed relatively more new vessels in the PCL-Col/NAC group than the control groups. This study developed novel PCL-Col/NAC scaffolds with an excellent hydroscopicity, tensile modulus and the ability to promote epidermal maturation and angiogenesis, demonstrating its promising potential in wound healing treatment. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.