In vitro antimicrobial effects of grape seed extract on peri-implantitis microflora in craniofacial implants

Objective:To determine the antimicrobial effects of grape seed on peri-implantitis microflora.Methods:The grape seed extract was tested against peri-implantitis microflora most commonly found in craniofacial implants including reference strains of Staphylococcus aureus(S.aureus),Escherichia coli(E.coli),Candida albicans(C.albicans)and clinical strains of S.aureus,Klebsiella pneumonia(K.pneumonia)and Candida parapsilosis(C.parapsilosis)by disk diffusion test.Minimum inhibitory concentrations(MIC)and minimum cidal concentrations(MCC)were determined using modified agar dilution millpore method.The extract was further combined with polyethylene glycol and propylene glycol,and was tested for antimicrobial effects.Results:Grape seed extract showed positive inhibitory effects with S.aureus at MIC of 0.625 mg/mL and MCC of1.25 mg/mL respectively.However the extracts showed minimal or no reactivity against strains of E.coli,K.pneumonia,C.parapsilosis and C.albicans.The use of grape seed extract in combination with polyethylene glycol and propylene glycol also showed dose dependent inhibitory effect on S.aureus.Conclusions:The results of the study showed that grape seed has potential antimicrobial effects which can be further studied and developed to be used in the treatment of infected skinabutment interface of craniofacial implants.

Maxillary subperiosteal implantitis that caused severe bone resorption of the maxilla with perforation of the maxillary sinus and sinusitis: A case report

Subperiosteal implants are generally used in the severely resorbed areas, and although dwindling in use, they have shown to be successful treatment options for the edentulous dental patients. We report a case of maxillary subperiosteal implantitis that caused sinusitis. A 59-year-old man was referred to our clinic in March 2003 with a chief complaint of pain and swelling in the bilateral upper molar region. He received a surgical operation for maxillary subperiosteal implant at another dental clinic in April 2001. CT scans demonstrated that the radiopacity of the right maxillary sinus extended to the ethmoid and frontal sinuses. Extensive surgical debridement was performed. The radiopacity of the right maxillary sinus in CT almost disappeared in a month. Two months later, the occlusal function was recovered using a new maxillary complete denture. The patient has had no symptoms and no occlusal disturbance by the denture for more than nine years.

Dental Implant Patients Grouped by the Brinkman Index: Their Attitude toward Smoking, Nicotine Dependence, and Knowledge of Peri-Implantitis

Purpose: This study investigated the attitude of patients, grouped by the Brinkman index, towards smoking by using the Kano Test for Social Nicotine Dependence (KTSND) and their knowledge of peri-implantitis. Methods: The participants were 3093 new patients who visited the Tokyo Medical and Dental University Hospital from January 2012 to December 2013 for an oral implant. The methodology included a questionnaire about sex, age, smoking status, daily average number of cigarettes, years of smoking, knowledge of peri-implantitis, and the KTSND. The patients were grouped according to their smoking status by calculating their Brinkman index (over 200 or not): current smokers with the possibility of nicotine dependence (BI(+)CS), current smokers with no possibility of nicotine dependence (BI(-)CS), ex-smokers (ES), and non-smokers (NS). The Brinkman index is obtained by multiplying one’s daily average number of cigarettes by the number of years they have been smoking. Results: Data were collected from 2182 respondents (response rate = 71%). The KTSND scores of BI(+)CS (16.89 ± 4.26) were significantly higher than the scores of ES (11.99 ± 4.52) and NS (11.53 ± 5.01). In current smokers, there were no significant differences between BI(+)CS and BI(-)CS. The patients replied “I don’t know” about peri-implantitis most often in all groups;however, there were no significant differences between the groups. Discussion: BI(+)CS were more dependent on nicotine in social situations than the other groups were. In Japan, a Brinkman index over 200 is required for a nicotine-dependence management fee to be instituted for health insurance treatment. This is a major concern for young smokers, who may be excluded from treatment because their years of smoking are substantially less. Results revealed that there were no significant differences between BI(+)CS and BI(-)CS. Therefore, it was suggested that the Brinkman index did not sufficiently group the participants.

Design multifunctional Mg–Zr coatings regulating Mg alloy bioabsorption

Magnesium(Mg)alloys are widely used for temporary bone implants due to their favorable biodegradability,cytocompatibility,hemocompatibility,and close mechanical properties to bone.However,rapid degradation and inadequate strength limit their applicability.To overcome this,the direct current magnetron sputtering technique is employed for surface coating in Mg-based alloys using various zirconium(Zr)content.This approach presents a promising strategy for simultaneously improving corrosion resistance,maintaining biocompatibility,and enhancing strength without compromising osseointegration.By leveraging Mg’s inherent biodegradability,it has the potential to minimize the need for secondary surgeries,thereby reducing costs and resources.This paper is a systematic study aimed at understanding the corrosion mechanisms of Mg–Zr coatings,denoted Mg-xZr(x=0–5 at.%).Zr-doped coatings exhibited columnar growth leading to denser and refined structures with increasing Zr content.XRD analysis confirmed the presence of the Mg(00.2)basal plane,shifting towards higher angles(1.15°)with 5 at.%Zr doping due to lattice parameter changes(i.e.,decrease and increase of“c”and“a”lattice parameters,respectively).Mg–Zr coatings exhibited“liquidphilic”behavior,while Young’s modulus retained a steady value around 80 GPa across all samples.However,the hardness has significantly improved across all samples’coating,reaching the highest value of(2.2±0.3)GPa for 5 at.%Zr.Electrochemical testing in simulated body fluid(SBF)at 37℃ revealed a significant enhancement in corrosion resistance for Mg–Zr coatings containing 1.0–3.4 at.%Zr.Compared with the 5 at.%Zr coating which exhibited a corrosion rate of 32 mm/year,these coatings displayed lower corrosion rates,ranging from 1 to 12 mm/year.This synergistic enhancement in mechanical properties and corrosion resistance,achieved with 2.0–3.4 at.%Zr,suggests potential ability for reducing stress shielding and controlled degradation performance,and consequently,promising functional biodegradable materials for temporary bone implants.

Systemic modulation of skeletal mineralization by magnesium implant promoting fracture healing: Radiological exploration enhanced with PCA-based machine learning in a rat femoral model

The clinical application of magnesium(Mg)and its alloys for bone fractures has been well supported by in vitro and in vivo trials.However,there were studies indicating negative effects of high dose Mg intake and sustained local release of Mg ions on bone metabolism or repair,which should not be ignored when developing Mg-based implants.Thus,it remains necessary to assess the biological effects of Mg implants in animal models relevant to clinical treatment modalities.The primary purpose of this study was to validate the beneficial effects of intramedullary Mg implants on the healing outcome of femoral fractures in a modified rat model.In addition,the mineralization parameters at multiple anatomical sites were evaluated,to investigate their association with healing outcome and potential clinical applications.Compared to the control group without Mg implantation,postoperative imaging at week 12 demonstrated better healing outcomes in the Mg group,with more stable unions in 3D analysis and high-mineralized bridging in 2D evaluation.The bone tissue mineral density(TMD)was higher in the Mg group at the non-operated femur and lumbar vertebra,while no differences between groups were identified regarding the bone tissue volume(TV),TMD and bone mineral content(BMC)in humerus.In the surgical femur,the Mg group presented higher TMD,but lower TV and BMC in the distal metaphyseal region,as well as reduced BMC at the osteotomy site.Principal component analysis(PCA)-based machine learning revealed that by selecting clinically relevant parameters,radiological markers could be constructed for differentiation of healing outcomes,with better performance than 2D scoring.The study provides insights and preclinical evidence for the rational investigation of bioactive materials,the identification of potential adverse effects,and the promotion of diagnostic capabilities for fracture healing.

Gelatin-Based Metamaterial Hydrogel Films with High Conformality for Ultra-Soft Tissue Monitoring

Implantable hydrogel-based bioelectronics(IHB)can precisely monitor human health and diagnose diseases.However,achieving biodegradability,biocompatibility,and high conformality with soft tissues poses significant challenges for IHB.Gelatin is the most suitable candidate for IHB since it is a collagen hydrolysate and a substantial part of the extracellular matrix found naturally in most tissues.This study used 3D printing ultrafine fiber networks with metamaterial design to embed into ultra-low elastic modulus hydrogel to create a novel gelatin-based conductive film(GCF)with mechanical programmability.The regulation of GCF nearly covers soft tissue mechanics,an elastic modulus from 20 to 420 kPa,and a Poisson’s ratio from-0.25 to 0.52.The negative Poisson’s ratio promotes conformality with soft tissues to improve the efficiency of biological interfaces.The GCF can monitor heartbeat signals and respiratory rate by determining cardiac deformation due to its high conformability.Notably,the gelatin characteristics of the biodegradable GCF enable the sensor to monitor and support tissue restoration.The GCF metamaterial design offers a unique idea for bioelectronics to develop implantable sensors that integrate monitoring and tissue repair and a customized method for endowing implanted sensors to be highly conformal with soft tissues.

Recent advances and innovations in the design and fabrication of wearable flexible biosensors and human health monitoring systems based on conjugated polymers

Wearable biosensors have received great interest as patient-friendly diagnostic technologies because of their high flexibility and conformability.The growing research and utilization of novel materials in designing wearable biosensors have accelerated the development of point-of-care sensing platforms and implantable biomedical devices in human health care.Among numerous potential materials,conjugated polymers(CPs)are emerging as ideal choices for constructing high-performance wearable biosensors because of their outstanding conductive and mechanical properties.Recently,CPs have been extensively incorporated into various wearable biosensors to monitor a range of target biomolecules.However,fabricating highly reliable CP-based wearable biosensors for practical applications remains a significant challenge,necessitating novel developmental strategies for enhancing the viability of such biosensors.Accordingly,this review aims to provide consolidated scientific evidence by summarizing and evaluating recent studies focused on designing and fabricating CP-based wearable biosensors,thereby facilitating future research.Emphasizing the superior properties and benefits of CPs,this review aims to clarify their potential applicability within this field.Furthermore,the fundamentals and main components of CP-based wearable biosensors and their sensing mechanisms are discussed in detail.The recent advancements in CP nanostructures and hybridizations for improved sensing performance,along with recent innovations in next-generation wearable biosensors are highlighted.CPbased wearable biosensors have been—and will continue to be—an ideal platform for developing effective and user-friendly diagnostic technologies for human health monitoring.

Deep brain implantable microelectrode arrays for detection and functional localization of the subthalamic nucleus in rats with Parkinson’s disease

The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise stimulation.In this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain depths.These results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned brains.In addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the STN.Moreover,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN localization.Compared with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned brains.This may be a cause of sleep and motor disorders associated with PD.Overall,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei.

Additively manufactured Ti–Ta–Cu alloys for the next-generation load-bearing implants

Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum(Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological,mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e.78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse infammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.

Interplay of laser power and pore characteristics in selective laser melting of ZK60 magnesium alloys:A study based on in-situ monitoring and image analysis

This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)alloys.High-speed in-situ monitoring was employed to visualise process signals in real-time,elucidating the dynamics of melt pools and vapour plumes under varying laser power conditions specifically between 40 W and 60 W.Detailed morphological analysis was performed using Scanning-Electron Microscopy(SEM),demonstrating a critical correlation between laser power and pore formation.Lower laser power led to increased pore coverage,whereas a denser structure was observed at higher laser power.This laser power influence on porosity was further confirmed via Optical Microscopy(OM)conducted on both top and cross-sectional surfaces of the samples.An increase in laser power resulted in a decrease in pore coverage and pore size,potentially leading to a denser printed part of Mg alloy.X-ray Computed Tomography(XCT)augmented these findings by providing a 3D volumetric representation of the sample internal structure,revealing an inverse relationship between laser power and overall pore volume.Lower laser power appeared to favour the formation of interconnected pores,while a reduction in interconnected pores and an increase in isolated pores were observed at higher power.The interplay between melt pool size,vapour plume effects,and laser power was found to significantly influence the resulting porosity,indicating a need for effective management of these factors to optimise the SLM process of Mg alloys.

Applications of SMILE-extracted lenticules in ophthalmology

AIM:To review recent innovations,challenges,and applications of small incision lenticule extraction(SMILE)extracted lenticule for treating ocular disorders.METHODS:A literature review was performed in the PubMed database,which was last updated on 30 December 2021.There was no limit regarding language.The authors evaluated the reference lists of the collected papers to find any relevant research.RESULTS:Due to the simplicity and accuracy of modern femtosecond lasers and the extensive development of SMILE surgery,many healthy human corneal stromal lenticules were extracted during surgery,motivating some professionals to investigate the SMILE lenticule reusability in different ocular disorders.In addition,new approaches had been developed to preserve,modify,and bioengineer the corneal stroma,leading to the optimal use of discarded byproducts such as lenticules from SMILE surgery.The lenticules can be effectively re-implanted into the autologous or allogenic corneas of human subjects to treat refractive errors,corneal ectasia,and corneal perforation and serve as a patch graft for glaucoma drainage devices with better cosmetic outcomes.CONCLUSION:SMILE-extracted lenticules could be a viable alternative to human donor corneal tissue.

Current knowledge for the risk factors of early permanent pacemaker implantation following transcatheter aortic valve replacement and what is next for the primary prevention?

In this editorial,we comprehensively summarized the preoperative risk factors of early permanent pacemaker implantation after transcatheter aortic valve replacement(TAVR)among patients with severe aortic stenosis from several renowned clinical studies and focused on the primary prevention of managing the modifiable factors,e.g.,paroxysmal atrial fibrillation before the TAVR.

Integrins and their potential roles in mammalian pregnancy

Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECM) interactions leading to assembly of integrin adhesion complexes(IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus(embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium(LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the scientific literature, the illustrations in this manuscript are drafted as Viking imagery for entertainment purposes.

Impact of High Sodium Diet on Neovascularization and Osseointegration around Titanium Implant:An in Vivo and in Vitro Study

Objective A high sodium(HS)diet is believed to affect bone metabolism processes.Clarifying its impact on osseointegration of titanium(Ti)implants holds significant implications for postoperative dietary management of implanted patients.Methods This investigation probed the impact of sodium ions(Na^(+))on neovascularization and osteogenesis around Ti implants in vivo,utilizing micro-computed tomography,hematoxylin and eosin staining,and immunohistochemical analyses.Concurrently,in vitro experiments assessed the effects of varied Na^(+)concentrations and exposure durations on human umbilical vein endothelial cells(HUVECs)and MC3T3-E1 cells.Results In vivo,increased dietary sodium(0.8%-6.0%)led to a substantial decline in CD34 positive HUVECs and new bone formation around Ti implants,alongside an increase in inflammatory cells.In vitro,an increase in Na^(+)concentration(140-150 mmol/L)adversely affected the proliferation,angiogenesis,and migration of HUVECs,especially with prolonged exposure.While MC3T3-E1 cells initially exhibited less susceptibility to high Na^(+)concentrations compared to HUVECs during short-term exposure,prolonged exposure to a HS environment progressively diminished their proliferation,differentiation,and osteogenic capabilities.Conclusion These findings suggest that HS diet had a negative effect on the early osseointegration of Ti implants by interfering with the process of postoperative vascularized bone regeneration.

In‑depth proteome characterization of endometrium and extraembryonic membranes during implantation in pig

Background Proteome characterization of the porcine endometrium and extraembryonic membranes is important to understand mother-embryo cross-communication.In this study,the proteome of the endometrium and cho-rioallantoic membrane was characterized in pregnant sows(PS)during early gestation(d 18 and 24 of gestation)and in the endometrium of non-pregnant sows(NPS)during the same days using LC-MS/MS analysis.The UniProtKB database and ClueGO were used to obtain functional Gene Ontology annotations and biological and functional networks,respectively.Results Our analysis yielded 3,254 and 3,457 proteins identified in the endometrium of PS and NPS,respectively;of these,1,753 being common while 1,501 and 1,704 were exclusive to PS and NPS,respectively.In addition,we iden-tified 3,968 proteins in the extraembryonic membranes of PS.Further analyses of function revealed some proteins had relevance for the immune system process and biological adhesion in endometrium while the embryonic chorion displayed abundance of proteins related to cell adhesion and cytoskeletal organization,suggesting they dominated the moment of endometrial remodeling,implantation and adhesion of the lining epithelia.Data are available via Pro-teomeXchange with identifier PXD042565.Conclusion This is the first in-depth proteomic characterization of the endometrium and extraembryonic mem-branes during weeks 3 to 4 of gestation;data that contribute to the molecular understanding of the dynamic environ-ment during this critical period,associated with the majority of pregnancy losses.

Graphene-calcium carbonate coating to improve the degradation resistance and mechanical integrity of a biodegradable implant

Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body environment.This necessitates the synthesis of a suitable coating that may improve the corrosion resistance of these implants without compromising their mechanical integrity.In this study,an AZ91 magnesium alloy,as a representative for a biodegradable Mg implant material,was modified with a thin reduced graphene oxide(RGO)-calcium carbonate(CaCO_(3))composite coating.Detailed analytical and in-vitro electrochemical characterization reveals that this coating significantly improves the corrosion resistance and mechanical integrity,and thus has the potential to greatly extend the related application field.

HVOF-sprayed HAp/S53P4 BG composite coatings on an AZ31 alloy for potential applications in temporary implants

Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration,considering that both phases have different reaction and dissolution rates under in-vitro conditions.In the present work,75%wt.HAp-25%wt.S53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/S53P4 BG composite coatings on a bioresorbable AZ31 alloy.The study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those coatings.Different characterization techniques,such as scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,were employed to characterize relevant structural and microstructural properties of the composite coatings.The results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved(max 550℃)and the differences in coefficients of thermal expansion.It was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the coatings.In addition,in-vitro electrochemical studies were performed on the obtained HAp/S53P4 BG composite coatings and compared against the uncoated AZ31 alloy.The results showed a significant decrease in hydrogen evolution(at least 98%)when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid(SBF).

Interlayer repair with porcine small intestinal submucosa versus internal repair with tragus cartilage in endoscopic tympanoplasty

Objective Endoscopic tympanoplasty includes various surgical methods,such as internal repair,interlayer repair,and external overlay.This technique requires autologous materials,allografts,and xenografts,which are used to repair tympanic membrane(TM)perforation.To obtain good results,appropriate surgical methods and repair materials should be selected.This study aims to assess the efficacy of repairing refractory TM perforations in the porcine small intestinal submucosa(SIS)during transcanal endoscopic type I tympanoplasty.Method A retrospective chart review was performed on patients who underwent TM perforation repair with porcine SIS and tragus cartilage between January 2022 and September 2022 at Sir Run Run Shaw Hospital,Zhejiang University School of Medicine.Perforation size,tympanic status,pre-and postoperative symptoms,follow-up data,wound healing rates,and hearing improvement were analysed.Results Of the 115 patients included in the study,56 underwent interlayer repair with porcine SIS of the TM,and 59 patients underwent internal repair with tragus cartilage.No significant difference was found between the two groups at baseline in terms of age,sex,disease course,perforation side,tympanic status,underlying disease,or preoperative infection.The total postoperative effective rate of interlayer implantation with porcine SIS was 91.07%(51 patients),and that of internal implantation with tragus cartilage was 88.14%(52 patients).No significant difference was found in terms of the graft success rate between the two surgical methods(p=0.887).Postoperative pure tone auditory(PTA)and air-bone gap(ABG)density significantly increased in both groups compared with before surgery(p<0.05).However,the postoperative PTA and ABG density were not significantly different 3 months post-surgery between the two groups(p>0.05).Compared to those in the internal implantation group,the patients in the interlayer group had a shorter operation duration(51.36±6.76 min vs.59.71±7.45 min,t=6.298,p<0.001)and less blood loss(11.91±2.61 mL vs.15.27±2.57 mL,t=7.019,p<0.001).Conclusions Our study suggests that the porcine SIS,as well as the tragus cartilage,has a high success rate in repairing irreversible TM perforation.Endoscopic tympanoplasty via interlayer implantation with porcine SIS offers distinct advantages,including the absence of donor-site incision and scar formation,and ease of graft modification and manipulation.

Peri-implant gas accumulation in response to magnesium-based musculoskeletal biomaterials:Reframing current evidence for preclinical research and clinical evaluation

Historically,the rapid degradation and massive gas release from magnesium(Mg)implants resulted in severe emphysema and mechanical failure.With the advent of new alloys and surface treatment methods,optimized Mg implants have re-entered clinics since last decade with reliable performance.However,the optimization aims at slowing down the degradation process,rather than exemption of the gas release.This study involved a systematic evaluation of current preclinical and clinical evidence,regarding the physical signs,symptoms,radiological features,pathological findings and complications potentially associated with peri±implant gas accumulation(PIGA)after musculoskeletal Mg implantation.The literature search identified 196 potentially relevant publications,and 51 papers were enrolled for further analysis,including 22 preclinical tests and 29 clinical studies published from 2005 to 2023.Various Mg-based materials have been evaluated in animal research,and the application of pure Mg and Mg alloys have been reported in clinical follow-ups involving multiple anatomical sites and musculoskeletal disorders.Soft tissue and intraosseous PIGA are common in both animal tests and clinical follow-ups,and potentially associated with certain adverse events.Radiological examinations especially micro-CT and clinical CT scans provide valuable information for quantitative and longitudinal analysis.While according to simulation tests involving Mg implantation and chemical processing,tissue fixation could lead to an increase in the volume of gas cavity,thus the results obtained from ex vivo imaging or histopathological evaluations should be interpreted with caution.There still lacks standardized procedures or consensus for both preclinical and clinical evaluation of PIGA.However,by providing focused insights into the topic,this evidence-based study will facilitate future animal tests and clinical evaluations,and support developing biocompatible Mg implants for the treatment of musculoskeletal disorders.

Influence of laser parameters on the microstructures and surface properties in laser surface modification of biomedical magnesium alloys

Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machinability,good biocompatibility,and biodegradability.The primary shortcoming of Mg-based implants is their low corrosion resistance in the physiological environment,which results in premature mechanical integrity loss before adequate healing and the production of excessive hydrogen gas,which is harmful to the body tissues and negatively affects the biocompatibility of the implant.Laser surface modification has recently received attention because it can improve the surface properties such as surface chemistry,roughness,topography,corrosion resistance,wear resistance,hydrophilicity,and thus cell response to the surface of the material.The composition and microstructures including textures and phases of laser-treated surfaces depend largely on the laser processing parameters(input laser power,laser scan velocity,frequency,pulse duration,pressure,gas circulation,working time,spot size,beam focal position,and laser track overlap)and the thermophysical properties of the substrate(solubility,melting point,and boiling point).This review investigates the impacts of various laser surface modification techniques including laser surface melting,laser surface alloying,laser cladding,laser surface texturing,and laser shock peening,and highlights their significance in improving the surface properties of biodegradable Mg alloys for implant applications.Additionally,we explore how different laser process parameters affect its composition,microstructure,and surface properties in each laser surface modification technique.