Micropatterned photothermal double-layer periosteum with angiogenesis-neurogenesis coupling effect for bone regeneration.

The abundant neurovascular network in the periosteal fibrous layer is essential for regulating bone homeostasis and repairing bone defects. However, the majority of the current studies only focus on the structure or function, and most of them merely involve osteogenesis and angiogenesis, lacking an in-depth study of periosteal neurogenesis. In this study, a photothermal double-layer biomimetic periosteum with neurovascular coupling was proposed.

Synthesis and characterization of rod-like amino acids/nanohydroxyapatite composites to inhibit osteosarcoma.

In this study, rod-like hydroxyapatite (HA) with uniform morphology and controllable particle size modified by doping with two different amino acids (alanine and threonine) was synthesized by a microwave hydrothermal method. The physical and chemical properties of the composites were tested by utilizing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), general thermogravimetric analysis (TG) and scanning electron microscopy (SEM). The SEM and XRD results show that the presence of amino acids (especially threonine) can significantly reduce the aspect ratio and crystallinity of hydroxyapatite.

Advances in the Treatment of Partial-Thickness Cartilage Defect.

Partial-thickness cartilage defects (PTCDs) of the articular surface is the most common problem in cartilage degeneration, and also one of the main pathogenesis of osteoarthritis (OA). Due to the lack of a clear diagnosis, the symptoms are often more severe when full-thickness cartilage defect (FTCDs) is present. In contrast to FTCDs and osteochondral defects (OCDs), PTCDs does not injure the subchondral bone, there is no blood supply and bone marrow exudation, and the nearby microenvironment is unsuitable for stem cells adhesion, which completely loses the ability of self-repair.

Mesoporous bioglass capsule composite injectable hydrogels with antibacterial and vascularization promotion properties for chronic wound repair.

Building an angiogenesis microenvironment and inhibiting wound infection are of great significance for chronic wound repair. In this paper, polydopamine-encapsulated mesoporous bioglass (MBG@PDA) capsules were constructed to realize the integration of angiogenesis and infection inhibition through the formation of a composite hydrogel with modified hyaluronic acid (HAMA) to promote wound healing. The experiments showed that the composite hydrogel had good adhesion and toughness and promoted the migration of fibroblasts to accelerate the epithelialization process.

One-Pot Preparation of Imidazole-Ring-Modified Graphitic Carbon Nitride Nanozymes for Colorimetric Glucose Detection.

Nanozymes are highly desired to overcome the shortcomings of natural enzymes, such as low stability, high cost and difficult storage during biosensing applications. Herein, by imitating the structure of natural enzymes, we propose a one-pot annealing process to synthesis imidazole-ring-modified graphitic carbon nitride (-CN-Im) with enhanced peroxidase-like activity. -CN-Im shows enhanced peroxidase-like activity by 46.

Photothermal Hydrogel Encapsulating Intelligently Bacteria-Capturing Bio-MOF for Infectious Wound Healing.

Chronic wounds are characterized by long-term inflammation and persistent infection, which make them difficult to heal. Therefore, an urgent desire is to develop a multifunctional wound dressing that can prevent wound infection and promote wound healing by creating a favorable microenvironment. In this study, a curcumin-based metal-organic framework (QCSMOF-Van), loaded with vancomycin and coated with quaternary ammonium salt chitosan (QCS), was prepared.

Dopamine-modified chitosan hydrogel for spinal cord injury.

Spinal cord injury (SCI) decreases people's both physical and psychological levels. The rehabilitation of SCI is still a clinical challenging process owing to the inflammatory environment for cell survival. Herein, we designed a dopamine-modified chitosan hydrogel to improve poor microenvironment of spinal cord injury.

Enhanced sciatic nerve regeneration by relieving iron-overloading and organelle stress with the nanofibrous P(MMD-co-LA)/DFO conduits.

Wallerian degeneration after peripheral nerve injury (PNI), that is, the autonomous degeneration of distal axons, leads to an imbalance of iron homeostasis and easily induces oxidative stress caused by iron overload. Inspired by the process of nerve degeneration and regeneration, the design of a functional electrospinning scaffold with iron chelating ability exhibited the importance of reconstructing a suitable microenvironment. Here, an electrospinning scaffold based on deferoxamine and poly(3(S)-methyl-morpholine-2,5-dionelactone) (PDPLA/DFO) was constructed.

Applications of Nano Hydroxyapatite as Adsorbents: A Review.

Nano hydroxyapatite (Ca(PO)(OH), HAp) has aroused widespread attention as a green and environmentally friendly adsorbent due to its outstanding ability in removing heavy metal ions, radio nuclides, organic pollutants and fluoride ions for wastewater treatment. The hexagonal crystal structure of HAp supports the adsorption mechanisms including ionic exchange reaction, surface complexation, the co-precipitation of new partially soluble phases and physical adsorption such as electrostatic interaction and hydrogen bonding. However, nano HAp has some drawbacks such as agglomeration and a significant pressure drop during filtration when used in powder form.

Folic acid-functionalized L-cys/ZnS:O nanoparticles for homologous targeting and photodynamic therapy of tumor cells.

The combination of photodynamic therapy (PDT) and fluorescence imaging provides a promising approach to theranostics. However, traditional photosensitizers (PSs) have low water solubility and lack active targeting ability. Our ingenious design used L-cys/ZnS:O (LZS) nanoparticles (NPs) modified with folic acid (FA), allowing them to easily enter tumor cells and accurately gather around the nucleus of cancer cells.

Novel Donor-Acceptor Conjugated Polymer-Based Nanomicelles for Photothermal Therapy in the NIR Window.

In this study, a novel donor-acceptor conjugated polymer PDPPDTP was designed and synthesized by D-A polymerization using 2,6-di(trimethyltin)--dithieno[3,2-:20,30-]pyrrole as the electron-donating (D) unit and 3,6-bis(5-bromothiophen-2-yl)-2,5-dihexadecylpyrrolo[3,4-]pyrrole-1,4-dione as the electron-accepting (A) unit. The prepared polymer has strong absorption in the near-infrared (NIR) range of 700-900 nm. Moreover, it shows excellent photothermal performance under irradiation at 808 nm.

Mesoporous hollow FeO nanoparticles regulate the behavior of neuro-associated cells through induction of macrophage polarization in an alternating magnetic field.

Magnetic iron oxide nanoparticles have shown great research value in the field of nerve regeneration because of their characteristics of satisfactory material properties and their ability to be stimulated by an external magnetic field to enhance the function of all aspects. Nevertheless, the impact of magnetic iron oxide nanoparticles on nerve regeneration regulated by macrophage polarization has not been well studied, and it is also not clear whether the introduction of the magnetic field has a further effect. Therefore, mesoporous hollow FeO nanoparticles (MHFPs) were synthesized.

Iron oxide nanoparticles with photothermal performance and enhanced nanozyme activity for bacteria-infected wound therapy.

Metal-based nanomaterials usually have broad-spectrum antibacterial properties, low biological toxicity and no drug resistance due to their intrinsic enzyme-like catalytic properties and external field (magnetic, thermal, acoustic, optical and electrical) responsiveness. Herein, iron oxide (FeO) nanoparticles (IONPs) synthesized by us have good biosafety, excellent photothermal conversion ability and peroxidase-like catalytic activity, which can be used to construct a photothermal-enzymes combined antibacterial treatment platform. IONPs with peroxide-like catalytic activity can induce HO to catalyze the production of •OH in a slightly acidic environment, thus achieving certain bactericidal effects and increasing the sensitivity of bacteria to heat.

Recent progress of nanomedicine in secreted phospholipase A2 as a potential therapeutic target.

Overexpressed secretory phospholipase A2 (sPLA2) is found in many inflammatory diseases and various types of cancer. sPLA2 can catalyze the hydrolysis of phospholipid sn-2 ester bonds to lysophosphatidylcholine and free fatty acids, and its catalytic substrate and downstream products mediate a series of cascade reactions and inflammatory responses. Furthermore, different subtypes of sPLA2 can participate in different physiological processes by driving unique lipid pathways.

Oxidized sodium alginate crosslinked silk fibroin composite scaffold for skin tissue engineering.

Engineering skin substitutes represent a prospective source of advanced therapy in repairing severe traumatic wounds. Sodium alginate (SA) and silk fibroin (SF) are natural biomaterials, which are widely used in tissue engineering and other fields because of their low price, high safety, and good biocompatibility. However, SA itself degrades slowly, its degradation mode is difficult to control, and the degradation products are difficult to remove from the body because of its high molecular weight.

A multifunctional chitosan hydrogel dressing for liver hemostasis and infected wound healing.

For the treatment of infected bleeding wounds, we compounded methacrylate anhydride dopamine (DAMA) and Zn-doped whitlockite nanoparticles (Zn-nWH) into methacrylate anhydride quaternized chitosan (QCSMA) to obtain a multifunctional hydrogel dressing (QCSMA/DAMA/Zn-nWH) with hemostasis, disinfection and wound healing promotion. QCSMA/DAMA/Zn-nWH exhibited good adhesion (0.031 MPa) and DPPH scavenging ability (94%), favorable biocompatibility (hemolysis ratio < 2%, no cytotoxicity), and showed a low BCI value (< 13%) in vitro coagulation test and could activate coagulation pathway.

Development of silk fibroin‑sodium alginate scaffold loaded silk fibroin nanoparticles for hemostasis and cell adhesion.

During wound healing process, it is essential to promote hemostasis and cell adhesion. Herein, we incorporated a scaffold with nanoparticles to improve the hemostatic properties and stimulate cell adhesion. The nanoparticles were prepared by self-assembling of silk fibroin, and the scaffold loaded nanoparticles were synthesized by crosslinking and freeze-drying.

Citric acid cross-linked chitosan for inhibiting oxidative stress after nerve injury.

Scaffold design is particularly important and necessary for soft tissue repair such as nerve tissue repair. In this article, we designed and manufactured a macroporous chitosan-based hydrogel with excellent cell compatibility and antioxidant properties. Here, the chitosan (CS) based hydrogel is obtained by repeated freezing and thawing using citric acid (CA) as a cross-linking agent.

GSH/enzyme-responsive 2-sulfonyl-1-methylimidazole prodrug for enhanced transdermal drug delivery and therapeutic efficacy against hyperthyroidis.

Novel GSH/enzyme-responsive anti-hyperthyroidism prodrugs designed for transdermal delivery of 2-sulfonyl-1- methylimidazole (MMI) were synthesized by a Michael addition reaction of MMI with propiolic acid (PA) followed by esterification with three long chain fatty alcohols and their structures were characterized by H NMR, C NMR and mass spectrometry. Their maximum steady state flux through rat skin in the PG/W solution was found to be more than 37-times faster than that of MMI. The result may be attributed to the improved lipophilicity of prodrug and rapid bioconversion.

3D Printed Personalized Nerve Guide Conduits for Precision Repair of Peripheral Nerve Defects.

The treatment of peripheral nerve defects has always been one of the most challenging clinical practices in neurosurgery. Currently, nerve autograft is the preferred treatment modality for peripheral nerve defects, while the therapy is constantly plagued by the limited donor, loss of donor function, formation of neuroma, nerve distortion or dislocation, and nerve diameter mismatch. To address these clinical issues, the emerged nerve guide conduits (NGCs) are expected to offer effective platforms to repair peripheral nerve defects, especially those with large or complex topological structures.

Oriented nanofibrous P(MMD-co-LA)/Deferoxamine nerve scaffold facilitates peripheral nerve regeneration by regulating macrophage phenotype and revascularization.

Delayed injured nerve regeneration remains a clinical problem, partly ascribing to the lack of regulation of regenerative microenvironment, topographical cues, and blood nourishment. Functional electrospun conduits have been established as an efficacious strategy to facilitate nerve regeneration by providing structural guidance, regulating the regenerative immune microenvironment, and improving vascular regeneration. However, the synthetic polymers conventionally used to fabricate electrospinning scaffolds, such as poly(L-lactic acid), poly(glycolic acid), and poly(lactic-co-glycolic acid), can cause aseptic inflammation due to acidic degradation products.

Silk fibroin nanofibrous scaffolds incorporated with microRNA-222 loaded chitosan nanoparticles for enhanced neuronal differentiation of neural stem cells.

Neural stem cells (NSCs) transplantation therapy is a promising method for neural tissue regeneration. How to enhance the neuronal differentiation of NSCs has been the most challenging aspect of NSCs application. Herein, the microRNA-222 loaded chitosan nanoparticles (miR-222/CS NPs) were incorporated with silk fibroin (SF) nanofibrous scaffolds to enhance neuronal differentiation of NSCs.

Improved functional recovery of rat transected spinal cord by peptide-grafted PNIPAM based hydrogel.

Facilitating angiogenesis, reducing the formation of glial scar tissue, and the occurrence of a strong inflammatory response are of great importance for the repair of central nerve damage. In our previous study, a temperature-sensitive hydrogel grafted with bioactive isoleucine-lysine-valine-alanine-valine (IKVAV) peptide was prepared and it showed regular three-dimensional porous structure, rapid (de)swelling performance and good biological activity. Therefore, in this study, we used this hydrogel scaffold to treat for SCI to study the effect of it to facilitate angiogenesis, inhibit the differentiation and adhesion of keratinocytes, and further reduce the formation of glial scar tissue.