Alzheimer’s disease (AD) is a prevalent neurodegenerative condition characterized by progressive cognitive decline and memory loss. As the incidence of AD continues to rise annually, researchers have shown keen interest in the active components found in natural plants and their neuroprotective effects against AD. Quercetin, a flavonol widely present in fruits and vegetables, has multiple biological effects including anticancer, anti-inflammatory, and antioxidant. Oxidative stress plays a central role in the pathogenesis of AD, and the antioxidant properties of quercetin are essential for its neuroprotective function. Quercetin can modulate multiple signaling pathways related to AD, such as Nrf2-ARE, JNK, p38 MAPK, PON2, PI3K/Akt, and PKC, all of which are closely related to oxidative stress. Furthermore, quercetin is capable of inhibiting the aggregation of β‑amyloid protein (Aβ) and the phosphorylation of tau protein, as well as the activity of β‑secretase 1 and acetylcholinesterase, thus slowing down the progression of the disease.The review also provides insights into the pharmacokinetic properties of quercetin, including its absorption, metabolism, and excretion, as well as its bioavailability challenges and clinical applications. To improve the bioavailability and enhance the targeting of quercetin, the potential of quercetin nanomedicine delivery systems in the treatment of AD is also discussed. In summary, the multifaceted mechanisms of quercetin against AD provide a new perspective for drug development. However, translating these findings into clinical practice requires overcoming current limitations and ongoing research. In this way, its therapeutic potential in the treatment of AD can be fully utilized.

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Electromagnetic fields can regulate the fundamental biological processes involved in bone remodeling. As a non-invasive physical therapy, electromagnetic fields with specific parameters have demonstrated therapeutic effects on bone remodeling diseases, such as fractures and osteoporosis. Electromagnetic fields can be generated by the movement of charged particles or induced by varying currents. Based on whether the strength and direction of the electric field change over time, electromagnetic fields can be classified into static and time-varying fields. The treatment of bone remodeling diseases with static magnetic fields primarily focuses on fractures, often using magnetic splints to immobilize the fracture site while studying the effects of static magnetic fields on bone healing. However, there has been relatively little research on the prevention and treatment of osteoporosis using static magnetic fields. Pulsed electromagnetic fields, a type of time-varying field, have been widely used in clinical studies for treating fractures, osteoporosis, and non-union. However, current clinical applications are limited to low-frequency, and research on the relationship between frequency and biological effects remains insufficient. We believe that different types of electromagnetic fields acting on bone can induce various “secondary physical quantities”, such as magnetism, force, electricity, acoustics, and thermal energy, which can stimulate bone cells either individually or simultaneously. Bone cells possess specific electromagnetic properties, and in a static magnetic field, the presence of a magnetic field gradient can exert a certain magnetism on the bone tissue, leading to observable effects. In a time-varying magnetic field, the charged particles within the bone experience varying Lorentz forces, causing vibrations and generating acoustic effects. Additionally, as the frequency of the time-varying field increases, induced currents or potentials can be generated within the bone, leading to electrical effects. When the frequency and power exceed a certain threshold, electromagnetic energy can be converted into thermal energy, producing thermal effects. In summary, external electromagnetic fields with different characteristics can generate multiple physical quantities within biological tissues, such as magnetic, electric, mechanical, acoustic, and thermal effects. These physical quantities may also interact and couple with each other, stimulating the biological tissues in a combined or composite manner, thereby producing biological effects. This understanding is key to elucidating the electromagnetic mechanisms of how electromagnetic fields influence biological tissues. In the study of electromagnetic fields for bone remodeling diseases, attention should be paid to the biological effects of bone remodeling under different electromagnetic wave characteristics. This includes exploring innovative electromagnetic source technologies applicable to bone remodeling, identifying safe and effective electromagnetic field parameters, and combining basic research with technological invention to develop scientifically grounded, advanced key technologies for innovative electromagnetic treatment devices targeting bone remodeling diseases. In conclusion, electromagnetic fields and multiple physical factors have the potential to prevent and treat bone remodeling diseases, and have significant application prospects.

[Objective] To investigate the protective effect of Salvia miltiorrhiza injection (SMI) on the kidneys of HBOC-CHP01 resuscitated haemorrhagic shock rats. [Methods] A 50% haemorrhagic shock rat model was established, with 12 rats divided into two groups: SMI + HBOC-CHP01 group and HBOC-CHP01 group, with 6 rats in each group. The rats in the SMI+ HBOC-CHP01 group were given an equal volume of HBOC-CHP01 for resuscitation after haemorrhagic shock, and an 8 mL/kg dose of SMI. Rats in the HBOC-CHP01 group were resuscitated by administering an equilibrium blood loss volume of HBOC-CHP01 and given an 8 mL/kg dose of 0.9% NaCl solution. Blood was taken from rats at five points: before bloodletting (baseline), during haemorrhagic shock (HS), immediately after resuscitation (RS0h), 1 h after resuscitation (RS1h), and 24 h after resuscitation (RS24h). A blood gas analyser was used to detect the lactate level (Lac), glucose content (Glu), residual base (BEecf), pH, bicarbonate (HCO3-), high iron haemoglobin (MetHb). White blood cells (WBC), platelets (PLT), haemoglobin content (Hb), carboxyhaemoglobin (COHb) were detected using a quintuple classification. Blood creatinine (SCr), uric acid (UA), kidney-related indexes were detected using biochemistry instrument. Kidney tissues of the rats were taken after 24 h of resuscitation and after execution, and the inflammation of kidneys of the rats of the two groups was analyzed using HE staining. Fluorescence staining was used to detect the level of ROS in the kidneys of rats in both groups. [Results] At RS 0h, the Beecf, Glu and Lac levels of rats in the SMI+HBOC-CHP01 group were significantly lower than those of rats in the HBOC-CHP01 group, and the pH level of rats in the SMI+HBOC-CHP01 group was significantly higher than that of rats in the HBOC-CHP01 group, and the Glu levels of rats in the SMI+HBOC-CHP01 group were significantly lower than those of rats in the HBOC-CHP01 group at RS 1h. At RS 0h, the WBC, PLT and COHb contents of rats in the SMI+HBOC-CHP01 group were all significantly higher than those of rats in the HBOC-CHP01 group, and at RS 1h, the WBC content of rats in the SMI+HBOC-CHP01 group was significantly higher than that of rats in the HBOC-CHP01 group; at RS 1h, the UA content of rats in the SMI+HBOC-CHP01 group was significantly lower than that of rats in the HBOC-CHP01 group; at RS 24h, the SCr content of rats in the SMI+HBOC-CHP01 group was significantly lower than that of rats in the HBOC-CHP01 group; at RS 24h, the inflammation level of kidney tissues of rats in the SMI+HBOC-CHP01 group was significantly lower than that of rats in the HBOC -CHP01 group rats, and the ROS and MPO levels in the kidney tissues of rats in the SMI+HBOC-CHP01 group were significantly lower than those of rats in the HBOC-CHP01 group. [Conclusion] The combination of Salvia miltiorrhiza injection during the resuscitation of rats with severe haemorrhagic shock by HBOC-CHP01 can alleviate renal injury by reducing inflammatory response and oxidative stress.

[Objective] To use Chitosan Methacryloyl (CSMA) loaded with artificial platelet-derived exosomes (aPexos) as the needle body material, and gelatin and carboxymethyl chitosan (CMCS) loaded with Epigallocatechin gallate(EGCG) as the backing material to prepare microneedles, aims to investigate the therapeutic effect and mechanism of aPexos-EGCG microneedles in the treatment of burn wound healing. [Methods] First, aPexos were extracted using ultrasound and gradient ultracentrifugation. The concentration, morphology, and growth factor content (TGF-β1, PDGF-BB, VEGF) of the exosomes were assessed using NTA, transmission electron microscopy, and ELISA kits. The aPexos and EGCG were then dissolved in the needle body and backing materials, respectively. The aPexos and EGCG were loaded into the needle body and backing layer, respectively. The morphology, mechanical properties, and puncture performance of the microneedles were examined, and the preparation conditions for the microneedles loaded with aPexos-EGCG were optimized. Finally, animal experiments and tissue staining were conducted to assess the efficacy of the aPexos-EGCG microneedles in promoting burn wound healing in rats. [Results] The size distribution of aPexos was mainly in the range of 50-150 nm, with an average diameter of 132.7±3.8 nm and an average concentration of approximately 2.88×10¹³±3.62×10¹² particles/mL. The concentrations of TGF-β1, PDGF-BB, and VEGF were approximately 1 363±135.9 ng/mL, 63.5±14.8 ng/mL, and 1 606.0±77.5 pg/mL, respectively. Mechanical property testing of the microneedles indicated that, compared with the blank microneedles, the drug-loaded microneedles had sufficient piercing ability to penetrate the stratum corneum of the skin. The results of the rat burn wound healing experiment showed that the wound healing rates of the d 3, d 7, aPexos-EGCG microneedle group compared to the control group showed significant differences, with respective values of (47.64±12.5)% vs (18.11±6.40)%, (87.45±5.57)% vs (79.85±5.03)%(P<0.05). Hematoxylin-eosin (HE) staining revealed more intact epidermal layers in the aPexos-EGCG microneedle group. Masson staining showed that the collagen deposition percentage in the aPexos-EGCG microneedle group was higher than in the control group. Immunofluorescence staining results indicated that the aPexos-EGCG microneedle group had a reduced content of M1-type macrophages and an increased content of M2-type macrophages. Additionally, the vascular markers CD31 and α-SMA showed elevated expression in this group, with significant differences compared to the other groups (P<0.05). [Conclusion] The aPexos-EGCG microneedle developed in this study exhibits good mechanical properties, capable of successfully penetrating the skin's stratum corneum and delivering aPexos and EGCG. aPexos promotes wound repair, while EGCG regulates the ratio of M1 and M2 macrophages at the wound site and suppresses the inflammatory response. This microneedle can effectively promote wound healing in rats with burn injuries, offering a novel approach for tissue repair.

BACKGROUND:There is still no consensus on the optimal internal fixation for the treatment of Pauwels Ⅲ femoral neck fracture,and most of the related finite element analyses have been performed using a single simplified loading condition,and the biomechanical properties of commonly used internal fixation devices need to be further investigated. OBJECTIVE:To analyze the biomechanical characteristics of Pauwels Ⅲ femoral neck fractures treated with cannulated compression screw,dynamic hip screw,and femoral neck system by finite element method under different loading conditions of single-leg standing loads and sideways fall loads. METHODS:The DICOM data of healthy adult femur were obtained by CT scanning,imported into Mimics 15.0 software to obtain the rough model of bone tissue.The data exported from Mimics were optimized by Geomagics software,and then three internal fixation models were built and assembled with the femur model according to the parameters of the clinical application of the cannulated compression screw,dynamic hip screw,and femoral neck system by using Pro/E software.Finally,the three internal fixation models were imported into Ansys software for loading and calculation to analyze the stress distribution and displacement of the femur and the internal fixation under different working conditions of single-leg standing loads and sideways fall loads,as well as the stress characteristics of the calcar femorale and Ward's triangle. RESULTS AND CONCLUSION:(1)Under the single-leg standing load and the sideways fall load,the proximal femoral stress of the three internal fixation models was mainly distributed above the fracture end of the femoral neck.The peak stress of the proximal femoral end,fracture end,Ward triangle,and calcar femorale of the three internal fixation models were the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(2)Under the single-leg standing load and the sideways fall load,the peak displacement of the proximal femur of the three internal fixation models was all located at the top of the femoral head,and the peak displacement was the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(3)The peak displacement of the three internal fixation models was all located at the top of the internal fixation device under the single-leg standing and sideways fall loading conditions,and the peak displacement values were the smallest in the femoral neck system internal fixation model and the largest in the cannulated compression screw internal fixation model.(4)The internal fixation stress of the three internal fixation models was mainly distributed in the area near the fracture end of the internal fixation device under the single-leg standing and sideways fall loads,and the peak value of internal fixation stress was the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(5)These results suggest that the mechanical stability of the femoral neck system is the best,but there may be a risk of stress shielding of the fracture end and calcar femorale.The stress of the internal fixation device of the femoral neck system is more dispersed,and the risk of internal fixation break is lower.

BACKGROUND:The use of fiber post to repair the endodontically treated non-carious cervical lesions teeth can change the stress distribution of the tooth and significantly reduce the risk of fracture of the affected tooth.However,the mechanical mechanism of fiber posts improving tooth fracture resistance and the optimal crown restoration for endodontically treated non-carious cervical lesions teeth are still debated. OBJECTIVE:To review the stress distribution pattern after restoration of endodontically treated non-carious cervical lesions teeth with fiber posts,the fracture resistance and fracture pattern under various stress states,and the latest research progress on fiber posts combined with different crown restorations. METHODS:The computerized search was applied in PubMed and CNKI to retrieve articles published from September 2008 to September 2023 with Chinese and English search terms"non-carious cervical lesions,endodontically treated teeth restoration,endodontically treated teeth stress distribution."Finally,56 articles were included for analysis. RESULTS AND CONCLUSION:The application of fiber post restoration for endodontically treated non-carious cervical lesion teeth can partially improve the cervical stress of the tooth without increasing the risk of vertical root fracture,can lead to a more consistent distribution of stress and enhance the tooth's ability to withstand fractures.Non-carious cervical lesion teeth with fiber posts that fracture would show favorable,restorable,or repairable fracture patterns.Fiber posts in combination with porcelain veneers or veneer-type inlays may become a more desirable minimally invasive restoration for repairing endodontically treated non-carious cervical lesion teeth.

OBJECTIVE To investigate the improvement effect and potential mechanism of Qingxue xiaozhi jiangtang formula on insulin resistance （IR） in type 2 diabetes mellitus （T2DM） rats. METHODS T2DM rat model was established by intraperitoneal injection of 30 mg/kg streptozotocin combined with high-fat and high-sugar diet. The rats were randomly divided into normal control group， model group， Qingxue xiaozhi jiangtang formula low-dose and high-dose groups （6.525， 13.05 g/kg， calculated by raw material） and metformin group （positive control， 0.18 g/kg）， with 8 rats in each group. Administration groups were given relevant medicine intragastrically； normal control group and model group were given constant volume of normal saline intragastrically， once a day， for consecutive 6 weeks. Body mass and fasting blood glucose （FBG） were determined， and oral glucose tolerance test was conducted. Serum fasting insulin （FINS） level was measured to calculate the insulin resistance index （HOMA-IR） and insulin sensitivity index （ISI）. Additionally， the level of serum lipids， liver function， oxidative stress indicators and inflammatory factors were assessed. The phosphorylation levels of kinase R-like endoplasmic reticulum kinase （PERK） and forkhead box O1 （FOXO1） protein in liver tissue of rats were determined. RESULTS Compared with model group， the body weight， ISI， the levels of high-density lipoprotein cholesterol and superoxide dismutase were increased significantly in Qingxue xiaozhi jiangtang formula high-dose group and metformin group （P＜0.05）； FBG， blood glucose level at 120 minutes of glucose loading， area under the curve of glucose， FINS， HOMA-IR， low-density lipoprotein cholesterol， total cholesterol， triglyceride， alanine transaminase， aspartate transaminase， alkaline phosphatase， malondialdehyde， interleukin-6， tumor necrosis factor-α， and C-reactive protein levels were significantly reduced （P＜ Δ0.05）； the pathological damage of liver tissue had significantlyimproved， and the phosphorylation levels of PERK and FOXO1 proteins in liver tissue were significantly decreased （P＜0.05）. CONCLUSIONS Qingxue xiaozhi jiangtang formula can regulate glucose and lipid metabolism， inflammation factor and oxidative stress levels， and alleviate insulin resistance in T2DM rats. Its mechanism of action may be related to the inhibition of the PERK/FOXO1 signaling pathway.

Based on advancements in modern medical research regarding the intricate connection between the endocrine and exocrine functions of the pancreas， as well as the relationship between pancreatic functions and traditional Chinese medicine （TCM） spleen system， this paper discussed the categorization of the pancreas. It is proposed that the pancreas is neither a true zang organ nor a fu organ， but possessed the attributes of an extraordinary fu-organ and can be classified under the spleen. The spleen governs transportation and transformation， ascent of the clear and dispersion of essence， which encompasses the endocrine and exocrine functions， and pancreatic enzymes and glucose-regulating hormones form the material basis for the spleen's function of dispersing essence. Diseases of the pancreas exhibit characteristics of both zang-organ deficiency and fu-organ excess， so treatment should simultaneously supplement zang-organ disease and regulate fu-organ disease when pancreas showing endocrine and exocrine co-morbidities， with focus on restoring the pancreas （spleen）'s dispersing essence function. Therapeutic strategies include supplementing spleen qi， nourishing spleen yin to strengthen spleen earth， unblocking spleen collaterals， raising spleen yang， and removing spleen turbidity to support the spleen's dispersing essence function， so as to replenish the essential qi of zang-fu organs， ensure their distribution throughout the body， and improve the endocrine and exocrine functions of the pancreas.