In silico identification of A1 agonists and A2a inhibitors in pain based on molecular docking strategies and dynamics simulations.

Most recently, the adenosine is considered as one of the most promising targets for treating pain, with few side effects. It exists in the central nervous system, and plays a key role in nociceptive afferent pathway. It is reported that the A1 receptor (A1R) could inhibit Ca2+ channels to reduce the pain like analgesic mechanism of morphine. And, A2a receptor (A2aR) was reported to enhance the accumulation of AMP (cAMP) and released peptides from sensory neurons, resulting in constitutive activation of pain. Much evidence showed that A1R and A2aR could be served as the interesting targets for the treatment of pain. Herein, virtual screening was utilized to identify the small molecule compounds towards A1R and A2aR, and top six molecules were considered as candidates via amber scores. The molecular dynamic (MD) simulations and molecular mechanics/generalized born surface area (MM/GBSA) were employed to further analyze the affinity and binding stability of the six molecules towards A1R and A2aR. Moreover, energy decomposition analysis showed significant residues in A1R and A2aR, including His1383, Phe1276, and Glu1277. It provided basics for discovery of novel agonists and antagonists. Finally, the agonists of A1R (ZINC19943625, ZINC13555217, and ZINC04698406) and inhibitors of A2aR (ZINC19370372, ZINC20176051, and ZINC57263068) were successfully recognized. Taken together, our discovered small molecules may serve as the promising candidate agents for future pain research.

Channel Selection of Ultracold Atom-Molecule Scattering in Dynamic Magnetic Fields.

We demonstrate that final states of ultracold molecules by scattering with atoms can be selectively produced using dynamic magnetic fields of multiple frequencies. We develop a multifrequency Floquet coupled channel method to study the channel selection by dynamic magnetic field control, which can be interpreted by a generalized quantum Zeno effect for the selected scattering channels. In particular, we use an atom-molecule spin-flip scattering to show that the transition to certain final states of the molecules in the inelastic scattering can be suppressed by engineered coupling between the Floquet states.

Felodipine blocks osteoclast differentiation and ameliorates estrogen-dependent bone loss in mice by modulating p38 signaling pathway.

Postmenopausal osteoporosis is one of the most common types of osteoporosis resulting from estrogen deficiency in elderly women. In addition, hypertension is another common disease in the elderly, and it has become an independent risk factor for osteoporosis and osteoporotic fractures. Here, we report for the first time that felodipine, a first-line antihypertensive agent, significantly prevents postmenopausal osteoporosis in addition to its vasodilation properties. Quantitative RT-PCR analysis revealed that treatment with felodipine significantly downregulated the genes associated with osteoclast differentiation. RNA-sequencing and western blotting suggested that felodipine could inhibit bone resorption by suppressing MAPK pathway phosphorylation. Moreover, micro-CT scanning and histological analysis in an ovariectomy (OVX)-induced bone-loss mouse model indicated that felodipine might be a potent drug for preventing osteoporotic fractures. Therefore, this study proposes an attractive and promising agent with vasodilation properties to treat postmenopausal osteoporosis.

Antibacterial and antibiofilm effects of flufenamic acid against methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) infections are one of the most serious surgery complications, and their prevention is of utmost importance. Flufenamic acid is a non-steroid anti-inflammatory drug approved for clinical use to relieve inflammation and pain in rheumatoid arthritis patients. In this study, we explored the antibacterial efficacy of flufenamic acid and the mechanisms underlying this effect. By using minimal inhibitory concentration (MIC), time-kill, resistance induction assays, and the antibiotic synergy test, we demonstrated that flufenamic acid inhibited the growth of methicillin-resistant staphylococci and did not induce resistance when it was used at the MIC. Furthermore, flufenamic acid acted synergistically with the beta-lactam antibiotic oxacillin and did not show significant toxicity toward mammalian cells. The biofilm inhibition assay revealed that flufenamic acid could prevent biofilm formation on medical implants and destroy the ultrastructure of the bacterial cell wall. RNA sequencing and quantitative RT-PCR indicated that flufenamic acid inhibited the expression of genes associated with peptidoglycan biosynthesis, beta-lactam resistance, quorum sensing, and biofilm formation. Furthermore, flufenamic acid efficiently ameliorated a local infection caused by MRSA in mice. In conclusion, flufenamic acid may be a potent therapeutic compound against MRSA infections and a promising candidate for antimicrobial coating of implants and surgical devices.

Age- and Parkinson's disease-related evaluation of gait by General Tau Theory.

The degeneration of postural control in the elderly and patients with Parkinson's disease (PD) can be debilitating and may lead to increased fall risk. This study evaluated the changes in postural control during gait affected by PD and aging using a new method based on the General Tau Theory. Fifteen patients with PD, 11 healthy old adults (HOs), and 15 healthy young adults (HYs) were recruited. Foot trajectories of each participant were monitored during walking by a three-camera Optotrak Certus(®) motion capture system. The anteroposterior direction of foot movement during stepping was analyzed by tau-G and tau-J guidance strategies. Two linear regression analyses suggested that the tau of the step-gap was strongly coupled onto the tau-J guidance during walking. The regression slope K could estimate the coupling ratio in the tau-coupling equation which reflects the performance of postural control during gait. The mean K value for the PD group, which was highest among the three groups, was approximately 0.5. Therefore, participants in the PD group walked with the poorest postural control and exhibited a relatively hard contact with the endpoint during stepping when compared with those in the HO and HY groups. The HY and HO groups obtained mean K values significantly lower than 0.5, which indicated that the gait was well controlled and ended at low speed with low deceleration. However, the HO group showed a decreased tendency for postural control, in which the mean K value was significantly higher than that of the HY group. The K value was moderately positively correlated with the double support time and negatively correlated with the stride length and walking speed. The tau-J coupling ratio can provide additional insight into gait disturbances and may serve as a reliable, objective, and quantitative tool to evaluate dynamic postural control during walking.

The time-dependent expression of α7nAChR during skeletal muscle wound healing in rats.

The study on time-dependent expression of α7 nicotine acetylcholine receptor (α7nAChR) was performed by immunohistochemistry, Western blotting, and real-time PCR during skeletal muscle wound healing in rats. Furthermore, co-localization of α7nAChR with macrophage or myofibroblast marker was detected by double immunofluorescence. A total of 50 Sprague-Dawley male rats were divided into control and contusion groups (3 h, 6 h, 12 h, 1 day, 3 days, 5 days, 7 days, 10 days, and 14 days post-injury). In the uninjured controls, α7nAChR positive staining was observed in the sarcolemma and sarcoplasm of normal myofibers. In wounded specimens, a small number of polymorphonuclear cells, a number of macrophages and myofibroblasts showed positive reaction for α7nAChR in contused zones. Morphometrically, the average ratios of α7nAChR-positive cells were over 50 % from 3 to 10 days after contusion, and exceeded 60 % at 5 and 7 days post-injury. Besides, the positive ratios of α7nAChR were <50 % at the other posttraumatic intervals. By Western blotting analysis, the average ratio of α7nAChR protein expression maximized at 7 days after injury, which was >2.13. Similarly, the relative quantity of α7nAChR mRNA expression peaked at 7 days post-wounding as compared with control by real-time PCR detection, showing a relative quantity of >2.65. In conclusion, the expression of α7nAChR is upregulated and temporally distributed in macrophages and myofibroblasts during skeletal muscle wound healing, which might be closely involved in inflammatory response and fibrotic repair after injury. Moreover, α7nAChR is promising as a useful marker for wound age determination of skeletal muscle.

Mg-based implants with a sandwiched composite coating simultaneously facilitate antibacterial and osteogenic properties.

Insufficient antibacterial effects and over-fast degradation are the main limitations of magnesium (Mg)-based orthopedic implants. In this study, a sandwiched composite coating containing a triclosan (TCS)-loaded poly(lactic acid) (PLA) layer inside and brushite (DCPD) layer outside was prepared on the surface of the Mg-Nd-Zn-Zr (denoted as JDBM) implant. In vitro degradation tests revealed a remarkable improvement in the corrosion resistance and moderate degradation rate. The drug release profile demonstrated a controllable and sustained TCS release for at least two weeks in vitro. The antibacterial rates of the implant were all over 99.8% for S. aureus, S. epidermidis, and E. coli, demonstrating superior antibacterial effects. Additionally, this coated JDBM implant exhibited no cytotoxicity but improved cell adhesion and proliferation, indicating excellent cytocompatibility. In vivo assays were conducted by implant-related femur osteomyelitis and osseointegration models in rats. Few bacteria were attached to the implant surface and the surrounding bone tissue. Furthermore, the coated JDBM implant exhibited more new bone formation than other groups due to the synergistic biological effects of released TCS and Mg2+, revealing excellent osteogenic ability. In summary, the JDBM implant with the sandwiched composite coating could significantly enhance the antibacterial activities and osteogenic properties simultaneously by the controllable release of TCS and Mg2+, presenting great potential for clinical transformation.

An adaptive biodegradable zinc alloy with bidirectional regulation of bone homeostasis for treating fractures and aged bone defects.

Healing of fractures or bone defects is significantly hindered by overactivated osteoclasts and inhibited osteogenesis in patients with abnormal bone metabolism. Current clinical approaches using titanium alloys or stainless steel provide mechanical support but have no biological effects on bone regeneration. Therefore, designing and fabricating degradable metal materials with sufficient mechanical strength and bidirectional regulation of both osteoblasts and osteoclasts is a substantial challenge. Here, this study first reported an adaptive biodegradable Zn-0.8 Mg alloy with bidirectional regulation of bone homeostasis, which promotes osteogenic differentiation by activating the Pi3k/Akt pathway and inhibits osteoclast differentiation by inhibiting the GRB2/ERK pathway. The anti-osteolytic ability of the Zn-0.8 Mg alloy was verified in a mouse calvarial osteolysis model and its suitability for internal fracture fixation with high-strength screws was confirmed in the rabbit femoral condyle fracture model. Furthermore, in an aged postmenopausal rat femoral condyle defect model, 3D printed Zn-0.8 Mg scaffolds promoted excellent bone regeneration through adaptive structures with good mechanical properties and bidirectionally regulated bone metabolism, enabling personalized bone defect repair. These findings demonstrate the substantial potential of the Zn-0.8 Mg alloy for treating fractures or bone defects in patients with aberrant bone metabolism.

Immunomodulatory biomaterials against bacterial infections: Progress, challenges, and future perspectives.

Bacterial infectious diseases are one of the leading causes of death worldwide. Even with the use of multiple antibiotic treatment strategies, 4.95 million people died from drug-resistant bacterial infections in 2019. By 2050, the number of deaths will reach 10 million annually. The increasing mortality may be partly due to bacterial heterogeneity in the infection microenvironment, such as drug-resistant bacteria, biofilms, persister cells, intracellular bacteria, and small colony variants. In addition, the complexity of the immune microenvironment at different stages of infection makes biomaterials with direct antimicrobial activity unsatisfactory for the long-term treatment of chronic bacterial infections. The increasing mortality may be partly attributed to the biomaterials failing to modulate the active antimicrobial action of immune cells. Therefore, there is an urgent need for effective alternatives to treat bacterial infections. Accordingly, the development of immunomodulatory antimicrobial biomaterials has recently received considerable interest; however, a comprehensive review of their research progress is lacking. In this review, we focus mainly on the research progress and future perspectives of immunomodulatory antimicrobial biomaterials used at different stages of infection. First, we describe the characteristics of the immune microenvironment in the acute and chronic phases of bacterial infections. Then, we highlight the immunomodulatory strategies for antimicrobial biomaterials at different stages of infection and their corresponding advantages and disadvantages. Moreover, we discuss biomaterial-mediated bacterial vaccines' potential applications and challenges for activating innate and adaptive immune memory. This review will serve as a reference for future studies to develop next-generation immunomodulatory biomaterials and accelerate their translation into clinical practice.

[Establishment of skin scald model in mice].

OBJECTIVE: To establish the model of skin scald in mice for the study of skin thermal injuries. METHODS: After anaesthetization mice were scalded in a 1 cm-diameter circle area on the central dorsum by boiling water at contact times: 10s or 25s. The mice were sacrificed at 1, 3, 5, 7 and 10 days after scald. The skin samples were collected and analyzed by gross and histopathological examinations. RESULTS: Deep II degree thermal injury involving full-thickness skin was observed in the 10s scald group. III degree thermal injury involving full-thickness skin and the dorsal skeletal muscle was observed in the 25 s scald group. CONCLUSION: A mouse skin scald model is established which is stable and can be used on the skin thermal injury in future research.

[The number of circulating fibrocytes of skeletal muscle in rats after contusion].

OBJECTION: To investigate the time-dependent appearance of circulating fibrocytes of skeletal muscle in rats after contusion. METHODS: The model of skeletal muscle wound was established in rat. The circulating fibrocytes in contused skeletal muscle were detected by CD45 and procollagen I double immunofluorescence staining method. RESULTS: In the control group, CD45- and procollagen I-positive cells were not detected in skeletal muscle. A few CD45 cells were observed aged from 6 h to 1 d after contusion. A few CD45- and procollagen I-positive cells (fibrocytes) initially gathered in injury area 3d after injury. The ratio of positive fibrocytes significantly increased 5 d after injury. The ratio of fibrocytes was highest at 7 d after contusion and then decreased. The volume of fibrocytes showed bigger with injury time increase compared with 3 d group. The expression of procollagen I and CD45 were weakened at 14d after injury. CONCLUSION: The circulating fibrocytes are detected in contused skeletal muscle in time-dependent pattern. Circulating fibrocytes may be a marker in the wound age determination for contused skeletal muscle.

Approaches to Biofunctionalize Polyetheretherketone for Antibacterial: A Review.

Due to excellent mechanical properties and similar elastic modulus compared with human cortical bone, polyetheretherketone (PEEK) has become one of the most promising orthopedic implant materials. However, implant-associated infections (IAIs) remain a challenging issue since PEEK is bio-inert. In order to fabricate an antibacterial bio-functional surface, modifications of PEEK had been widely investigated. This review summarizes the modification strategies to biofunctionalize PEEK for antibacterial. We will begin with reviewing different approaches, such as surface-coating modifications and controlled release of antimicrobials. Furthermore, blending modifications and 3D printing technology were discussed. Finally, we compare the effects among different approaches. We aimed to provide an in-depth understanding of the antibacterial modification and optimize the design of the PEEK orthopedic implant.

Construction and Comparison of Predictive Models for Length of Stay after Total Knee Arthroplasty: Regression Model and Machine Learning Analysis Based on 1,826 Cases in a Single Singapore Center.

The purpose of this study was to develop a predictive model for length of stay (LOS) after total knee arthroplasty (TKA). Between 2013 and 2014, 1,826 patients who underwent TKA from a single Singapore center were enrolled in the study after qualification. Demographics of patients with normal and prolonged LOS were analyzed. The risk variables that could affect LOS were identified by univariate analysis. Predictive models for LOS after TKA by logistic regression or machine learning were constructed and compared. The univariate analysis showed that age, American Society of Anesthesiologist level, diabetes, ischemic heart disease, congestive heart failure, general anesthesia, and operation duration were risk factors that could affect LOS (p < 0.05). Comparing with logistic regression models, the machine learning model with all variables was the best model to predict LOS after TKA, of whose area of operator characteristic curve was 0.738. Machine learning algorithms improved the predictive performance of LOS prediction models for TKA patients.

AmV2O5 with Binary Phases as High-Performance Cathode Materials for Zinc-Ion Batteries: Effect of the Pre-Intercalated Cations A and Reversible Transformation of Coordination Polyhedra.

In this work, five vanadium oxide materials with a series of pre-intercalated cations A (AmV2O5), including Zn2+, Mg2+, NH4+, Li+, and Ag+, have been successfully prepared by a two-step method. All of them possess binary monoclinic and orthorhombic V2O5 phases with an open layered structure that allows the ionic storage and diffusion of hydrated cations. The interlayer space for the monoclinic V2O5 phase is strongly dependent on the radii of hydrated cations A, while the one for the orthorhombic V2O5 phase remains the same regardless of the radii of cations A. Among them, AmV2O5 with pre-intercalated Zn2+ (ZVO) has the best storage ability of Zn2+ with a reversible capacity close to 400 mAh g-1, and AmV2O5 with pre-intercalated Ag+ shows the highest rate capacity with a nearly 40% capacity retention at a current of 20 A g-1 (≈25 C). Kinetic studies have clearly shown that pseudocapacitive behavior dominates the electrochemical reaction on ZVO. During the Zn2+ (de)intercalation reaction, a highly reversible transformation of binary monoclinic or orthorhombic V2O5 phases into a single triclinic ZnxV2O5·nH2O phase is demonstrated on ZVO. Vanadium atoms are identified as the redox centers that undergo the mutual transition among the chemical states of V3+, V4+, and V5+. They together with oxygen atoms constitute reasonable V-O coordination polyhedra to generate a layered structure with a suitable interlayer space for the insertion or removal of zinc ions. Actually, the intrinsic coordination chemistry changes between VO5 square pyramids and VO6 octahedra account for the phase transformation during the Zn2+-(de)intercalation reaction.

Felodipine enhances aminoglycosides efficacy against implant infections caused by methicillin-resistant Staphylococcus aureus, persisters and biofilms.

Methicillin-resistant Staphylococcus aureus (MRSA), biofilms, and persisters are three major factors leading to recurrent and recalcitrant implant infections. Although antibiotics are still the primary treatment for chronic implant infections in clinical, only few drugs are effective in clearing persisters and formed biofilms. Here, felodipine, a dihydropyridine calcium channel blocker, was reported for the first time to have antibacterial effects against MRSA, biofilm, and persisters. Even after continuous exposure to sub-lethal concentrations of felodipine, bacteria are less likely to develop resistance. Besides, low doses of felodipine enhances the antibacterial activity of gentamicin by inhibiting the expression of protein associated with aminoglycoside resistance (aacA-aphD). Next, biofilm eradication test and persisters killing assay suggested felodipine has an excellent bactericidal effect against formed biofilms and persisters. Furthermore, the result of protein profiling, and quantitative metabonomics analysis indicated felodipine reduce MRSA virulence (agrABC), biofilm formation and TCA cycle. Then, molecular docking showed felodipine inhibit the growth of persisters by binding to the H pocket of ClpP protease, which could lead to substantial protein degradation. Furthermore, murine infection models suggested felodipine in combination with gentamicin alleviate bacterial burden and inflammatory response. In conclusion, low dose of felodipine might be a promising agent for biomaterial delivery to enhance aminoglycosides efficacy against implant infections caused by MRSA, biofilm, and persisters.

Multi-Mode Antibacterial Strategies Enabled by Gene-Transfection and Immunomodulatory Nanoparticles in 3D-Printed Scaffolds for Synergistic Exogenous and Endogenous Treatment of Infections.

As research on refractory Staphylococcus aureus-related implant infection intensifies, certain challenges remain, including low antibiotic concentrations within infected areas, immune escape achieved by intracellular bacteria, myeloid-derived suppressor cells (MDSCs) inducing regional immunosuppression, and recurrence of residual pathogenic bacteria after drug suspension. Herein, a novel antimicrobial system to simultaneously address these issues is proposed. Specifically, an oxygen-species-responsive 3D-printed scaffold with shell-core nanoparticles is designed, which are loaded with an antimicrobial peptide plasmid (LL37 plasmid) and have LL37 grafted on their surface (LL37@ZIF8-LL37). The surface-grafted LL37 directly kills S. aureus and, following entry into cells, the nanoparticles kill intracellular bacteria. Moreover, in vitro and in vivo, following translation of the LL37 plasmid, cells function as factories of the antimicrobial peptide, thereby generating a continuous, prolonged antibacterial effect at the site of infection. This system significantly reduces the abnormal increase in MDSCs within the infected microenvironment, thus relieving the immunosuppressive state and restoring a protective antimicrobial immune response. Hence, this proposed antimicrobial system provides an antimicrobial immune response and a novel strategy for S. aureus-related infections by offering a combined active antimicrobial and immunotherapeutic strategy, thereby significantly reducing the recurrence rate following recovery from implant-associated infections.

3D Printing for Bone-Cartilage Interface Regeneration.

Due to the vasculature defects and/or the avascular nature of cartilage, as well as the complex gradients for bone-cartilage interface regeneration and the layered zonal architecture, self-repair of cartilage and subchondral bone is challenging. Currently, the primary osteochondral defect treatment strategies, including artificial joint replacement and autologous and allogeneic bone graft, are limited by their ability to simply repair, rather than induce regeneration of tissues. Meanwhile, over the past two decades, three-dimension (3D) printing technology has achieved admirable advancements in bone and cartilage reconstruction, providing a new strategy for restoring joint function. The advantages of 3D printing hybrid materials include rapid and accurate molding, as well as personalized therapy. However, certain challenges also exist. For instance, 3D printing technology for osteochondral reconstruction must simulate the histological structure of cartilage and subchondral bone, thus, it is necessary to determine the optimal bioink concentrations to maintain mechanical strength and cell viability, while also identifying biomaterials with dual bioactivities capable of simultaneously regenerating cartilage. The study showed that the regeneration of bone-cartilage interface is crucial for the repair of osteochondral defect. In this review, we focus on the significant progress and application of 3D printing technology for bone-cartilage interface regeneration, while also expounding the potential prospects for 3D printing technology and highlighting some of the most significant challenges currently facing this field.

Photosensitizer Nanodot Eliciting Immunogenicity for Photo-Immunologic Therapy of Postoperative Methicillin-Resistant Staphylococcus aureus Infection and Secondary Recurrence.

The treatment of postoperative infection caused by multidrug-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), has become an intractable clinical challenge owing to its low therapeutic efficacy and high risk of recurrence. Apart from imperfect antibacterial therapies, induction of insufficient immunogenicity, required for the successful clearance of a pathogen, may also contribute to the problem. Herein, an ultra-micro photosensitizer, AgB nanodots, using photothermal therapy, photodynamic therapy, and Ag+ ion sterilization, are utilized to efficiently clear invading MRSA both in vitro and in vivo. AgB nanodots are also found to upregulate host immunogenicity in a murine model and establish immunological memory by promoting the upregulated expression of danger signals that are commonly induced by stress-related responses, including sudden temperature spikes or excess reactive oxygen production. These stimulations boost the antibacterial effects of macrophages, dendritic cells, T cells, or even memory B cells, which is usually defined as infection-related immunogenic cell death. Hence, the proposed AgB nanodot strategy may offer a novel platform for the effective treatment of postoperative infection while providing a systematic immunotherapeutic strategy to combat persistent infections, thereby markedly reducing the incidence of recurrence following recovery from primary infections.

Nicotinic acetylcholine receptor α7 subunit is time-dependently expressed in distinct cell types during skin wound healing in mice.

Recent studies have shown that nicotinic acetylcholine receptor alpha7 subunit (nAChRα7) plays an important role in regulation of inflammation, angiogenesis and keratinocyte biology, but little is known about its expression after the skin is wounded. A preliminary study on time-dependent expression and distribution of nAChRα7 was performed by immunohistochemistry, Western blotting and RT-PCR during skin wound healing in mice. After a 1-cm-long incision was made in the skin of the central dorsum, mice were killed at intervals ranging from 6 h to 14 days post-injury. In uninjured skin controls, nAChRα7 positive staining was observed in epidermis, hair follicles, sebaceous glands, vessel endothelium and resident dermal fibroblastic cells. In wounded specimens, a small number of polymorphonuclear cells, a large number of mononuclear cells (MNCs) and fibroblastic cells (FBCs) showed positive reaction for nAChRα7 in the wound zones. Simultaneously, nAChRα7 immunoreactivity was evident in endothelial-like cells of regenerated vessels and neoepidermis. By morphometric analysis, an up-regulation of nAChRα7 expression was verified at the inflammatory phase after skin injury and reached a peak at the proliferative phase of wound healing. The expression tendency was further confirmed by Western blotting and RT-PCR assay. By immunofluorescent staining for co-localization, the nAChRα7-positive MNCs and FBCs in skin wounds were identified as macrophages, fibrocytes and myofibroblasts. A number of nAChRα7-positive myofibroblasts were also CD45 positive, indicating that they originated from differentiation of fibrocytes. The results demonstrate that nAChRα7 is time-dependently expressed in distinct cell types, which may be closely involved in inflammatory response and repair process during skin wound healing.

Time-dependent expression and distribution of monoacylglycerol lipase during the skin-incised wound healing in mice.

The study investigated the expression of monoacylglycerol lipase (MGL) during the skin-incised wound healing in mice and applicability of the time-dependent expression of MGL to wound age determination by immunofluorescent staining, Western blotting, and real-time PCR. Furthermore, cell types were identified by double immunofluorescence. A total of 45 BALB/c male mice were used in this study. After a 1.5-cm-long incision in the central dorsum skin, mice were killed at intervals ranging from 6 h to 14 days, followed by the sampling of wound margin. In the control, there was a low-level expression of MGL in the epidermis, hair follicles, and glandulae sebaceae. In the injured skin, MGL immunoreactivity was mainly detected in the neutrophils, macrophages, and myofibroblasts. Morphometrically, the average ratios of MGL-positive cells were more than 50% at 5 and 7 days post-wounding, whereas it was <50% at the other posttraumatic intervals. By Western blotting analysis, the average ratio of MGL protein expression was highest at 5 days after injury, which had a ratio of >2.30. Similarly, the relative quantity of MGL mRNA expression maximized at posttraumatic 5 days in comparison with control as detected by real-time PCR, with an average ratio of >2.54. In conclusion, MGL expression is detected in neutrophils, macrophages, and myofibroblasts and significantly up-regulated, suggesting that it may play roles in response to inflammation during skin-incised wound healing. From the viewpoint of forensic pathology, MGL detection is applicable to skin wound age determination.