Unleashing the Potential of Electroactive Hybrid Biomaterials and Self‑Powered Systems for Bone Therapeutics

The incidence of large bone defects caused by traumatic injury is increasing worldwide,and the tissue regeneration process requires a long recovery time due to limited self-healing capability.Endogenous bioelectrical phenomena have been well recognized as critical biophysical factors in bone remodeling and regeneration.Inspired by bioelectricity,electrical stimulation has been widely considered an external intervention to induce the osteogenic lineage of cells and enhance the synthesis of the extracellular matrix,thereby accelerating bone regeneration.With ongoing advances in biomaterials and energy-harvesting techniques,electroactive biomaterials and self-powered systems have been considered biomimetic approaches to ensure functional recovery by recapitulating the natural electrophysiological microenvironment of healthy bone tissue.In this review,we first introduce the role of bioelectricity and the endogenous electric field in bone tissue and summarize different techniques to electrically stimulate cells and tissue.Next,we highlight the latest progress in exploring electroactive hybrid biomaterials as well as self-powered systems such as triboelectric and piezoelectric-based nanogenerators and photovoltaic cell-based devices and their implementation in bone tissue engineering.Finally,we emphasize the significance of simulating the target tissue’s electrophysiological microenvironment and propose the opportunities and challenges faced by electroactive hybrid biomaterials and self-powered bioelectronics for bone repair strategies.

Recent Strategies and Advances in Hydrogel‑Based Delivery Platforms for Bone Regeneration

Bioactive molecules have shown great promise for effectively regulating various bone formation processes,rendering them attractive therapeutics for bone regeneration.However,the widespread application of bioactive molecules is limited by their low accumulation and short half-lives in vivo.Hydrogels have emerged as ideal carriers to address these challenges,offering the potential to prolong retention times at lesion sites,extend half-lives in vivo and mitigate side effects,avoid burst release,and promote adsorption under physiological conditions.This review systematically summarizes the recent advances in the development of bioactive molecule-loaded hydrogels for bone regeneration,encompassing applications in cranial defect repair,femoral defect repair,periodontal bone regeneration,and bone regeneration with underlying diseases.Additionally,this review discusses the current strategies aimed at improving the release profiles of bioactive molecules through stimuli-responsive delivery,carrier-assisted delivery,and sequential delivery.Finally,this review elucidates the existing challenges and future directions of hydrogel encapsulated bioactive molecules in the field of bone regeneration.

Limited evidence to support demineralized bone matrix in foot and ankle surgical procedures:A systematic review

BACKGROUND Demineralized bone matrix(DBM)is a commonly utilized allogenic bone graft substitute to promote osseous union.However,little is known regarding outcomes following DBM utilization in foot and ankle surgical procedures.AIM To evaluate the clinical and radiographic outcomes following DBM as a biological adjunct in foot and ankle surgical procedures.METHODS During May 2023,the PubMed,EMBASE and Cochrane library databases were systematically reviewed to identify clinical studies examining outcomes following DBM for the management of various foot and ankle pathologies.Data regarding study characteristics,patient demographics,subjective clinical outcomes,radiological outcomes,complications,and failure rates were extracted and analyzed.In addition,the level of evidence(LOE)and quality of evidence(QOE)for each individual study was also assessed.Thirteen studies were included in this review.RESULTS In total,363 patients(397 ankles and feet)received DBM as part of their surgical procedure at a weighted mean follow-up time of 20.8±9.2 months.The most common procedure performed was ankle arthrodesis in 94 patients(25.9%).Other procedures performed included hindfoot fusion,1st metatarsophalangeal joint arthrodesis,5th metatarsal intramedullary screw fixation,hallux valgus correction,osteochondral lesion of the talus repair and unicameral talar cyst resection.The osseous union rate in the ankle and hindfoot arthrodesis cohort,base of the 5th metatarsal cohort,and calcaneal fracture cohort was 85.6%,100%,and 100%,respectively.The weighted mean visual analog scale in the osteochondral lesions of the talus cohort improved from a pre-operative score of 7.6±0.1 to a post-operative score of 0.4±0.1.The overall complication rate was 27.2%,the most common of which was non-union(8.8%).There were 43 failures(10.8%)all of which warranted a further surgical procedure.CONCLUSION This current systematic review demonstrated that the utilization of DBM in foot and ankle surgical procedures led to satisfactory osseous union rates with favorable wound complication rates.Excellent outcomes were observed in patients undergoing fracture fixation augmented with DBM,with mixed evidence supporting the routine use of DBM in fusion procedures of the ankle and hindfoot.However,the low LOE together with the low QOE and significant heterogeneity between the included studies reinforces the need for randomized control trials to be conducted to identify the optimal role of DBM in the setting of foot and ankle surgical procedures.

Continuum of glucose and bone metabolism impairment across autonomous cortisol secretion: A cross-sectional study

BACKGROUND Autonomous cortisol secretion(ACS)is linked to a higher prevalence of metabolic abnormalities and an increased risk of major adverse cardiovascular events.AIM To evaluate glucose and bone metabolism in patients with ACS using a continuous glucose monitoring system(CGMS)and dual-energy X-ray absorptiometry(DXA).METHODS Patients diagnosed with ACS,including Cushing syndrome,mild ACS(MACS),and nonfunctional adrenal incidentaloma(NFAI),were recruited for this study.Glucose variability and glycemic status were assessed using CGMS.Regional bone mineral content(BMC),bone mineral density(BMD),and bone area(BA)were evaluated using DXA.CGMS-and DXA-derived parameters were compared across the subgroups of ACS.Correlation analysis was performed to examine relationships between varying degrees of cortisol secretion,measured by cortisol after 1 mg overnight dexamethasone suppression test(DST)or 24-hour urine free cortisol(24h UFC),and CGMS-or DXA-derived parameters.RESULTS A total of 64 patients with ACS were included in this study:19 with Cushing syndrome,11 with MACS,and 34 with NFAI.Glucose variability,time above range(TAR),and time in range(TIR)along with specific areal BMC,BMD,and BA,differed significantly between groups of Cushing syndrome and NFAI.A significant positive correlation was observed between glucose variability or TAR and cortisol after 1 mg overnight DST or 24h UFC.By contrast,TIR,along with regional BMC,BMD,and BA,were negatively correlated with varying degrees of cortisol secretion.CONCLUSION Glucose and bone metabolism impairments are on a continuum alteration from NFAI to MACS and Cushing syndrome.Prompt attention should be given to these patients with ACS,especially those with mild hormone secretion.Parameters of glucose variability and glycemic status along with bone condition in regions rich in cancellous bone will provide valuable information.

Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

Impact of dietary nutrition regimens based on body composition analysis on bone metabolism in Alzheimer’s disease patients

BACKGROUND Body composition analysis(BCA)is primarily used in the management of conditions such as obesity and endocrine disorders.However,its potential in providing nutritional guidance for patients with Alzheimer’s disease(AD)remains relatively unexplored.AIM To explore the clinical efficacy of BCA-based dietary nutrition scheme on bone metabolism in AD patients.METHODS This retrospective study included 96 patients with AD complicated by osteoporosis who were admitted to The Third Hospital of Quzhou between January 2023 and December 2024.Based on data from previous similar studies,the patients were randomly assigned to either a routine diet(RD)group(n=48)or a personalized nutrition(PN)group(n=48).The RD group received conventional dietary guidance,while the PN group received individualized diet intervention measures based on human BCA.The intervention period lasted for 12 weeks.Bone mineral density(BMD),body mass index(BMI),muscle mass,mineral content,osteocalcin,25-hydroxyvitamin D,procollagen type I N-terminal propeptide(PINP),beta C-terminal telopeptide of type I collagen(β-CTX),and serum calcium were measured and compared between the two groups before and 12 weeks after the intervention.RESULTS No significant differences were observed between groups in terms of age,sex,height,BMI,or other baseline data(P>0.05).In both groups,BMI did not show significant changes after the intervention(P>0.05),whereas muscle mass and mineral content were significantly increased(P<0.05).After the intervention,BMI in the PN group did not differ significantly from that of the RD group,but muscle mass and mineral content were significantly higher in the PN group(P<0.05).After the intervention,a higher proportion of patients in the PN group had a T score>-1 compared to the RD group(P<0.05).The mini-mental state examination(MMSE)score was similar in both groups before the intervention.However,12 weeks after the intervention,the MMSE score in the PN group was significantly higher than that in the RD group(P<0.05).In both groups,the MMSE score significantly increased 12 weeks post-intervention compared to pre-intervention levels(P<0.05).Before the intervention,the levels of osteocalcin,serum calcium,PINP,β-CTX,and 25-hydroxyvitamin D were not significantly different between the two groups(P>0.05).After 12 weeks of intervention,the PN group exhibited higher levels of osteocalcin,serum calcium,and 25-hydroxyvitamin D,as well as lower levels of PINP andβ-CTX,compared to the RD group(P<0.05).In both groups,osteocalcin,serum calcium,and 25-hydroxyvitamin D levels were significantly higher,while PINP andβ-CTX levels were significantly lower after 12 weeks of intervention compared to baseline(P<0.05).CONCLUSION The human BCA-based dietary nutrition regimen plays a crucial role in improving BMD and bone metabolism,with effects that surpass those of conventional nutrition strategies.The findings of this study provide strong evidence for the nutritional management of AD patients.

AAV-mediated expression of p65shRNA and bone morphogenetic protein 4 synergistically enhances chondrocyte regeneration

BACKGROUND:Adeno-associated virus(AAV)gene therapy has been proven to be reliable and safe for the treatment of osteoarthritis in recent years.However,given the complexity of osteoarthritis pathogenesis,single gene manipulation for the treatment of osteoarthritis may not produce satisfactory results.Previous studies have shown that nuclear factorκB could promote the inflammatory pathway in osteoarthritic chondrocytes,and bone morphogenetic protein 4(BMP4)could promote cartilage regeneration.OBJECTIVE:To test whether combined application of AAV-p65shRNA and AAV-BMP4 will yield the synergistic effect on chondrocytes regeneration and osteoarthritis treatment.METHODS:Viral particles containing AAV-p65-shRNA and AAV-BMP4 were prepared.Their efficacy in inhibiting inflammation in chondrocytes and promoting chondrogenesis was assessed in vitro and in vivo by transfecting AAV-p65-shRNA or AAV-BMP4 into cells.The experiments were divided into five groups:PBS group;osteoarthritis group;AAV-BMP4 group;AAV-p65shRNA group;and BMP4-p65shRNA 1:1 group.Samples were collected at 4,12,and 24 weeks postoperatively.Tissue staining,including safranin O and Alcian blue,was applied after collecting articular tissue.Then,the optimal ratio between the two types of transfected viral particles was further investigated to improve the chondrogenic potential of mixed cells in vivo.RESULTS AND CONCLUSION:The combined application of AAV-p65shRNA and AAV-BMP4 together showed a synergistic effect on cartilage regeneration and osteoarthritis treatment.Mixed cells transfected with AAV-p65shRNA and AAV-BMP4 at a 1:1 ratio produced the most extracellular matrix synthesis(P<0.05).In vivo results also revealed that the combination of the two viruses had the highest regenerative potential for osteoarthritic cartilage(P<0.05).In the present study,we also discovered that the combined therapy had the maximum effect when the two viruses were administered in equal proportions.Decreasing either p65shRNA or BMP4 transfected cells resulted in less collagen II synthesis.This implies that inhibiting inflammation by p65shRNA and promoting regeneration by BMP4 are equally important for osteoarthritis treatment.These findings provide a new strategy for the treatment of early osteoarthritis by simultaneously inhibiting cartilage inflammation and promoting cartilage repair.

Efficacy and safety of C-arm computed tomography-guided microwave ablation with percutaneous osteoplasty for flat bone metastases

BACKGROUND Flat bone metastases are common in patients with advanced cancers,often resulting in severe pain,limited mobility,and reduced quality of life(QOL).Traditional treatment options,such as radiotherapy or systemic therapies,often fail to provide sufficient pain relief or improve functional outcomes in these patients.Microwave ablation(MWA)offers advantages,such as shorter pro-cedure times and larger ablation zones,while percutaneous osteoplasty(PO)enhances bone stability and prevents pathological fractures.Despite these be-nefits,the combination of these techniques for treating flat bone metastases re-mains underexplored.AIM To evaluate the efficacy and safety of C-arm computed tomography(CT)-guided MWA combined with PO for managing painful flat bone metastases,focusing on pain relief,functional improvement,and QOL enhancement.METHODS A total of 45 patients with refractory moderate-to-severe pain resulting from flat bone metastases who underwent C-arm CT-guided MWA combined with PO between January 2015 and January 2021 were included.The efficacy of the pro-cedure was assessed by changes in the visual analog scale(VAS),Oswestry disability index(ODI),and QOL,as well as the occurrence of complications.Tumor response was evaluated using RECIST v1.1 and mRECIST criteria,with overall response rate(ORR)and disease control rate(DCR)as the primary end-points.RESULTS No serious complications were observed in any of the patients.A significant reduction in VAS and ODI was noted at 1 week,1 month,and 3 months post-procedure.A marked improvement in QOL was observed at all follow-up points.Bone cement extravasation was observed in 10 patients;however,none exhibited significant clinical symptoms.Based on RECIST v1.1,the ORR was 26.7%and the DCR was 88.9%.The mRECIST evaluation revealed a higher ORR of 51.1%and DCR of 88.9%.CONCLUSION C-arm CT-guided MWA with PO provides a dependable and effective strategy for managing flat bone metastases.It demonstrates significant pain relief,improved functional outcomes,and enhanced QOL.This treatment combination also shows promising tumor response rates with a low complication profile.

Association between body mass index and lumbar spine volumetric bone mineral density in diabetic and non-diabetic patients

BACKGROUND The association between body mass index(BMI)and bone mineral density(BMD)has shown inconsistent results,varying by sex and skeletal site.Despite normal or elevated bone mass,individuals with type 2 diabetes have an increased risk of hip and vertebral fractures.AIM To assess lumbar spine trabecular volumetric BMD(vBMD)across different BMI categories in individuals with and without diabetes.METHODS This cross-sectional study included 966 men over 50 years old and 1001 postmenopausal women from the Pinggu Metabolic Disease Study.The vBMD of lumbar vertebrae 2 through 4 was measured using quantitative computed tomography.Total adipose tissue,subcutaneous adipose tissue(SAT),visceral adipose tissue(VAT),and lumbar skeletal muscle area were also quantified.RESULTS In men with obesity(P=0.038)and overweight(P=0.032),vBMD was significantly higher in the diabetes group compared to non-diabetic men.After adjusting for age and sex,no significant saturation effect between BMI and BMD was found in participants with diabetes or in women without diabetes.However,a BMI threshold of 22.33 kg/m²indicated a saturation point for vBMD in nondiabetic men.Independent predictors of vBMD in men included age(r=-0.387,P<0.001),BMI(r=0.130,P=0.004),and VAT(r=-0.145,P=0.001).For women,significant predictors were age(r=-0.594,P<0.001),BMI(r=0.157,P=0.004),VAT(r=-0.112,P=0.001),and SAT(r=-0.068,P=0.035).CONCLUSION The relationship between BMI and trabecular vBMD differs in individuals with and without diabetes.Overweight and obese men with diabetes exhibit higher vBMD.

Bone marrow mesenchymal stem cells promote uterine healing by activating the PI3K/AKT pathway and modulating inflammation in rat models

BACKGROUND Uterine injury can cause uterine scarring,leading to a series of complications that threaten women’s health.Uterine healing is a complex process,and there are currently no effective treatments.Although our previous studies have shown that bone marrow mesenchymal stem cells(BMSCs)promote uterine damage repair,the underlying mechanisms remain unclear.However,exploring the specific regulatory roles of BMSCs in uterine injury treatment is crucial for further understanding their functions and enhancing therapeutic efficacy.AIM To investigate the underlying mechanism by which BMSCs promote the process of uterine healing.METHODS In in vivo experiments,we established a model of full-thickness uterine injury and injected BMSCs into the uterine wound.Transcriptome sequencing was per-formed to determine the enrichment of differentially expressed genes at the wound site.In in vitro experiments,we isolated rat uterine smooth muscle cells(USMCs)and cocultured them with BMSCs to observe the interaction between BMSCs and USMCs in the microenvironment.RESULTS We found that the differentially expressed genes were mainly related to cell growth,tissue repair,and angiogenesis,while the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)pathway was highly enriched.Quantitative reverse-transcription polymerase chain reaction was used to validate differentially expressed genes,and the results demonstrated that BMSCs can upregulate genes related to regeneration and downregulate genes related to inflammation.Coculturing BMSCs promoted the migration and proliferation of USMCs,and the USMC microenvironment promoted the myogenic differentiation of BMSCs.Finally,we validated the PI3K/AKT pathway in tissues and cells and showed that BMSCs activate the PI3K/AKT pathway to promote the regeneration of uterine smooth muscle both in vivo and in vitro.CONCLUSION BMSCs upregulated uterine wound regeneration and anti-inflammatory factors and enhanced uterine smooth muscle proliferation through the PI3K/AKT pathway both in vivo and in vitro.

Raloxifene对去卵巢大鼠子宫内膜的影响

目的 比较EVISTA(Raloxifene)和Livial用于治疗去卵巢大鼠骨质疏松时对子宫内膜的影响。方法 32只 4月龄雌性SD大鼠随机分为 4组 :假手术组、模型组、Raloxifene组及Livial组 ,每组 8只 ,用药实验 6 0d ,处死大鼠取子宫 ,对大鼠子宫内膜进行形态学检查。结果 模型组、Ralox ifene组和Livial组大鼠子宫内膜腺体数目均比假手术组少 ,P <0 0 1;Raloxifene组与模型组子宫内膜形态相似 :子宫内膜腺体缩小 ,内膜上皮较薄 ;Livial组子宫内膜上皮有增宽趋势 ,少数可见轻至中度鳞状上皮化生和不典型增生。结论 在治疗去卵巢大鼠骨质疏松的过程中 ,Raloxifene对子宫内膜无明显作用 ,Livial对大鼠可能有促进子宫内膜上皮生长趋势和不典型增生 。

Raloxifene与利维爱对去卵巢大鼠血脂的影响

目的观察Raloxifene(EVISTA)和利维爱(Livial)用于治疗去卵巢大鼠骨质疏松时对血脂的影响。方法32只4月龄雌性SD大鼠随机分为4组 :假手术组、模型组、Raloxifene组及利维爱组 ,每组8只 ,用药60天 ,采血分离血清 ,测定血清总胆固醇(TC)、甘油三脂(TG)、高密度脂蛋白(HDL_C)、低密度脂蛋白(LDL_C) ,对各组血脂测定值进行比较。结果大鼠去卵巢75天后 ,模型组血脂已有变化 ,表现为TC增高 ,HDL_C降低 ,TC、LDL_C差异无显著性 ;两药物组与模型组比较血脂改善 ,但调脂结果各不相同 :利维爱与Raloxifene均有降低TG、升高HDL_C的作用 ,前者降TC强于后者 ,对LDL_C无明显影响 ;后者升HDL_C强于前者 ,同时还有降低LDL_C作用 ;二者对TG均无明显作用 ;结论大鼠去卵巢后将发生血脂紊乱 ,Raloxifene。

Antagonism of estrogen-mediated cell proliferation by raloxifene in prevention of ageing-related prostatic hyperplasia

Estrogen has important roles in the initiation and development of benign prostatic hyperplasia （BPH）. Regulators of the estrogen receptor （ER） are tissue- and cell-specific. We evaluated the effect of estrogen antagonist, raloxifene （Ral）, on the prevention and treatment of BPH by investigating its effect on the proliferation of two different prostate cell lines： a stromal cell line, WPMY-1, and a benign prostatic hyperplasia epithelial cell line, BPH-1. We additionally evaluated its effect on prostatic hyperplasia induced by estrogen and androgen in a rat model. The effect of Ral on the prevention of prostatic hyperplasia was analyzed by haematoxylin and eosin staining and quantitative immunohistochemistry （IHC） for proliferating cell nuclear antigen and α-smooth muscle actin. In vitro and in vivo, tamoxifen （Tam）, another anti-estrogen drug, and finasteride （Fin）, a drug for the clinical treatment of BPH, served as efficacy controls. The in vitro data showed that neither Ral nor Tam alone affected the proliferation of WPMY-1 and BPH-1, but both antagonized the effect of oestradiol in promoting the proliferation of the two cells. Results from the IHC staining of the rat prostates indicated that, similar to Tam and Fin, Ral inhibited the proliferation of stromal cells in vivo. Interestingly, in contrast to Tam, both Ral and Fin inhibited the proliferation of epithelial cells. Furthemore, Ral treatment much strongly decreased the number of prostatic acini and the surrounding layers of smooth muscle cells than Fin （P 〈 0.05）. Our data showed for the first time that Ral may have a role in the response of the rat prostate to selective ER modulators.

Crosstalk between Wnt and bone morphogenetic protein signaling during osteogenic differentiati

Mesenchymal stem cells(MSCs)originate from many sources,including the bone marrow and adipose tissue,and differentiate into various cell types,such as osteoblasts and adipocytes.Recent studies on MSCs have revealed that many transcription factors and signaling pathways control osteogenic development.Osteogenesis is the process by which new bones are formed;it also aids in bone remodeling.Wnt/β-catenin and bone morphogenetic protein(BMP)signaling pathways are involved in many cellular processes and considered to be essential for life.Wnt/β-catenin and BMPs are important for bone formation in mammalian development and various regulatory activities in the body.Recent studies have indicated that these two signaling pathways contribute to osteogenic differen-tiation.Active Wnt signaling pathway promotes osteogenesis by activating the downstream targets of the BMP signaling pathway.Here,we briefly review the molecular processes underlying the crosstalk between these two pathways and explain their participation in osteogenic differentiation,emphasizing the canonical pathways.This review also discusses the crosstalk mechanisms of Wnt/BMP signaling with Notch-and extracellular-regulated kinases in osteogenic differentiation and bone development.

Hydrogel loaded with bone marrow stromal cell-derived exosomes promotes bone regeneration by inhibiting inflammatory responses and angiogenesis

BACKGROUND Bone healing is a complex process involving early inflammatory immune regu-lation,angiogenesis,osteogenic differentiation,and biomineralization.Fracture repair poses challenges for orthopedic surgeons,necessitating the search for efficient healing methods.AIM To investigate the underlying mechanism by which hydrogel-loaded exosomes derived from bone marrow mesenchymal stem cells(BMSCs)facilitate the process of fracture healing.METHODS Hydrogels and loaded BMSC-derived exosome(BMSC-exo)gels were charac-terized to validate their properties.In vitro evaluations were conducted to assess the impact of hydrogels on various stages of the healing process.Hydrogels could recruit macrophages and inhibit inflammatory responses,enhance of human umbilical vein endothelial cell angiogenesis,and promote the osteogenic differen-tiation of primary cranial osteoblasts.Furthermore,the effect of hydrogel on fracture healing was confirmed using a mouse fracture model.RESULTS The hydrogel effectively attenuated the inflammatory response during the initial repair stage and subsequently facilitated vascular migration,promoted the formation of large vessels,and enabled functional vascularization during bone repair.These effects were further validated in fracture models.CONCLUSION We successfully fabricated a hydrogel loaded with BMSC-exo that modulates macrophage polarization and angiogenesis to influence bone regeneration.

Icariin accelerates bone regeneration by inducing osteogenesisangiogenesis coupling in rats with type 1 diabetes mellitus

BACKGROUND Icariin(ICA),a natural flavonoid compound monomer,has multiple pharmacological activities.However,its effect on bone defect in the context of type 1 diabetes mellitus(T1DM)has not yet been examined.AIM To explore the role and potential mechanism of ICA on bone defect in the context of T1DM.METHODS The effects of ICA on osteogenesis and angiogenesis were evaluated by alkaline phosphatase staining,alizarin red S staining,quantitative real-time polymerase chain reaction,Western blot,and immunofluorescence.Angiogenesis-related assays were conducted to investigate the relationship between osteogenesis and angiogenesis.A bone defect model was established in T1DM rats.The model rats were then treated with ICA or placebo and micron-scale computed tomography,histomorphometry,histology,and sequential fluorescent labeling were used to evaluate the effect of ICA on bone formation in the defect area.RESULTS ICA promoted bone marrow mesenchymal stem cell(BMSC)proliferation and osteogenic differentiation.The ICA treated-BMSCs showed higher expression levels of osteogenesis-related markers(alkaline phosphatase and osteocalcin)and angiogenesis-related markers(vascular endothelial growth factor A and platelet endothelial cell adhesion molecule 1)compared to the untreated group.ICA was also found to induce osteogenesis-angiogenesis coupling of BMSCs.In the bone defect model T1DM rats,ICA facilitated bone formation and CD31hiEMCNhi type H-positive capillary formation.Lastly,ICA effectively accelerated the rate of bone formation in the defect area.CONCLUSION ICA was able to accelerate bone regeneration in a T1DM rat model by inducing osteogenesis-angiogenesis coupling of BMSCs.

Prolonged cholestasis after raloxifene and fenofibrate interaction: A case report

Assigning causality in drug-induced liver injury is challenging particularly when more than one drug could be responsible. We report a woman on long-term therapy with raloxifen who developed acute cholestasis shortly after starting fenofibrate. The picture evolved into chronic cholestasis. We hypothesized that an interaction at the metabolic level could have triggered the presentation of hepatotoxicity after a very short time of exposure to fenofibrate in this patient. The findings of an overexpression of vascular endothelial growth factor in the liver biopsy suggest that angiogenesis might play a role in the persistance of toxic cholestasis.

Raloxifene-loaded and aptamer-bonded exosomes induce autophagic and apoptotic death in HeLa cells by enhancing the lysosomotropic effect

Background:Raloxifene,a selective estrogen receptor modulator,is also known to be a lysosomotropic agent.The bioavailability of raloxifene is around 2%due to extensive hepatic transport.Exosomes are nanosized vesicles that are naturally released from cells.Method:In this study,exosomes released from HeLa cervical cancer cells were loaded with raloxifene to increase its bioavailability,and an aptamer was attached to the exosome membrane for targeting only HeLa cells.Characterization of exosomes isolated from HeLa cells was performed by transmission electron microscopy,zeta sizer,and western blotting.In addition,the cytotoxic,apoptotic,autophagic,and lysosomotropic effects of the prepared Exo-Apt-Ral formulation on HeLa cervical cancer cells were investigated.Results:According to zeta analysis,the sizes of the empty exosome and Exo-Apt-Ral formulation were measured as 66±12 and 120±21 nm,respectively.There was a rise in the lysosomal permeability of HeLa cells after the Exo-Apt-Ral application.In addition,both apoptotic and autophagic death mechanisms were triggered in HeLa cells after the Exo-Apt-Ral application.Conclusion:This study showed that raloxifene functionalized by loading into aptamer-bound exosomes can be a new targeted drug carrier system for cervical cancer.

In vitro study of influence of raloxifene on the growth of human ovarian cancer cell line Skov 3

Objective: To study the effects of raloxifene on the growth of the human ovarian cancer cell line Skov3 and on the expression of cell proliferative antigen Ki-67 in vitro.Methods: The proliferative capacity of the ovarian cancer cell line Skov3 in the culture medium with raloxifene was evaluated by the microculture tetrazolium assay (MTT) and the expression of cell proliferation was appraised by the immunohistochemical staining of ki-67.Results: The growth of ovarian cancer cell line Skov3 was inhibited by raloxifene at high concentrations, while a trend of growth promotion at initial then followed by growth inhibition was found when raloxifene was at low concentrations. Raloxifene at high concentrations not only significantly reduced the expression of Ki-67 but also destroyed the cell structure.Conclusion: Raloxifene does not stimulate the growth of human ovarian cancer cell line Skov3significantly.

Calcium-chelating peptides from rabbit bone collagen:characterization,identification and mechanism elucidation

This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.