Preclinical testing of immunotoxicity for animal-derived dermal materials

Animal derived materials have been widely used in biomedical products owing to their good biocompatibility and appropriate mechanical properties.It is crucial to evaluate the immunotoxicity of such materials in preclinical testing to prevent severe immune responses in patients.In this study,a pipeline of immunotoxicity tests was established to evaluate animal-derived materials before de-cellularization and final products.This pipeline contains a serial of animal tests on BALB/c mice and an in vitro quantification test for a-Gal antigen.It is wellrecognized that the interaction between materials and patients profoundly alters immune responses,thus,a comprehensive dataset including body weight,immune organ coefficient,histopathology,peripheral hematology,serum immunoglobulin level,spleen lymphocyte proliferation rate,and their subpopulation was created and analyzed using the SPSS tool.These results clearly suggested that the de-cellularized materials possessed better biocompatibility,in addition,the a-Gal antigen content was effectively decreased by 96.0%after decellularization.Thus,this study confirmed that this multi-step enzymatic de-cellularization treatment is a potent method to reduce the immunotoxicity of animal-derived biomaterials.Moreover,the experimental pipeline will likely be transferable to other biomedical materials and products.

Radiotherapy as valid modality for hepatocellular carcinoma with portal vein tumor thrombosis

Although the current standard treatment for hepatocellular carcinoma(HCC) with portal vein tumor thrombosis(PVTT) is sorafenib, many previous studies have established the need for a reliable local modality for PVTT control, which is a major cause of liver function deterioration and metastasis. Additionally, there is growing evidence for the prognostic significance of PVTT classification according to the location of tumor thrombosis. Favorable outcomes can be obtained by applying local modalities, including surgery or transarterial chemoembolization, especially in second-order or distal branch PVTT. Rapid control of PVTT could maintain or improve liver function and reduce intrahepatic as well as distant metastasis. Radiotherapy(RT) is one of the main locoregional treatment modalities in oncologic fields, but has rarely been used in HCC because of concerns regarding hepatic toxicity. However, with the development of advanced techniques, RT has been increasingly applied in HCC management. Randomized studies have yet to definitively prove the benefit of RT, but several comparative studies have justified the application of RT in HCC. The value of RT is especially noticeable in HCC with PVTT; several prospective and retrospective studies have reported favorable outcomes, including a 40% to 60% objective response rate and median overall survival of 15 mo to 20 mo in responders. In this review, we evaluate the role of RT as an alternative local modality in HCC with PVTT.

Proton therapy for hepatocellular carcinoma:Current knowledges and future perspectives

Hepatocellular carcinoma(HCC) is the second leading cause of cancer-related death, as few patients can be treated with currently available curative local modalities. In patients with HCC where curative modalities are not feasible, radiation therapy(RT) has emerged as an alternative or combination therapy. With the development of various technologies, RT has been increasingly used for the management of HCC. Among these advances, proton beam therapy(PBT) has several unique physical properties that give it a finite range in a distal direction, and thus no exit dose along the beam path. Therefore, PBT has dosimetric advantages compared with X-ray therapy for the treatment of HCC. Indeed, various reports in the literature have described the favorable clinical outcomes and improved safety of PBT for HCC patients compared with X-ray therapy. However, there are some technical issues regarding the use of PBT in HCC, including uncertainty of organ motion and inaccuracy during calculation of tissue density and beam range, all of which may reduce the robustness of a PBT treatment plan. In this review, we discuss the physical properties, current clinical data, technical issues, and future perspectives on PBT for the treatment of HCC.

Risk prediction platform for pancreatic fistula after pancreatoduodenectomy using artificial intelligence

BACKGROUND Despite advancements in operative technique and improvements in postoperative managements,postoperative pancreatic fistula(POPF)is a life-threatening complication following pancreatoduodenectomy(PD).There are some reports to predict POPF preoperatively or intraoperatively,but the accuracy of those is questionable.Artificial intelligence(AI)technology is being actively used in the medical field,but few studies have reported applying it to outcomes after PD.AIM To develop a risk prediction platform for POPF using an AI model.METHODS Medical records were reviewed from 1769 patients at Samsung Medical Center who underwent PD from 2007 to 2016.A total of 38 variables were inserted into AI-driven algorithms.The algorithms tested to make the risk prediction platform were random forest(RF)and a neural network(NN)with or without recursive feature elimination(RFE).The median imputation method was used for missing values.The area under the curve(AUC)was calculated to examine the discriminative power of algorithm for POPF prediction.RESULTS The number of POPFs was 221(12.5%)according to the International Study Group of Pancreatic Fistula definition 2016.After median imputation,AUCs using 38 variables were 0.68±0.02 with RF and 0.71±0.02 with NN.The maximal AUC using NN with RFE was 0.74.Sixteen risk factors for POPF were identified by AI algorithm:Pancreatic duct diameter,body mass index,preoperative serum albumin,lipase level,amount of intraoperative fluid infusion,age,platelet count,extrapancreatic location of tumor,combined venous resection,co-existing pancreatitis,neoadjuvant radiotherapy,American Society of Anesthesiologists’score,sex,soft texture of the pancreas,underlying heart disease,and preoperative endoscopic biliary decompression.We developed a web-based POPF prediction platform,and this application is freely available at http://popfrisk.smchbp.org.CONCLUSION This study is the first to predict POPF with multiple risk factors using AI.This platform is reliable(AUC 0.74),so it could be used to select patients who need especially intense therapy and to preoperatively establish an effective treatment strategy.

Microelectrode glucose biosensor based on nanoporous platinum/graphene oxide nanostructure for rapid glucose detection of tomato and cucumber fruits

A microelectrode glucose biosensor based on a three-dimensional hybrid nanoporous platinum/graphene oxide nanostructure was developed for rapid glucose detection of tomato and cucumber fruits.The nanostructure was fabricated by a two-step modification method on a microelectrode for loading a larger amount of glucose oxidase.The nanoporous structure was prepared on the surface of the platinum microelectrode by electrochemical etching,and then graphene oxide was deposited on the prepared nanoporous electrode by electrochemical deposition.The nanoporous platinum/graphene oxide nanostructure had the advantage of improving the effective surface area of the electrode and the loading quantity of glucose oxidase.As a result,the biosensor achieved a wide range of 0.1-20.0 mmol/L in glucose detection,which had the ability to accurately detect the glucose content.It was found that the three-dimensional hybrid nanostructure on the electrode surface realized the rapid direct electrochemistry of glucose oxidase.Therefore,the biosensor achieved high glucose detection sensitivity 11.64μA·L/(mmol.cm^(2)),low detection limit(13μmol/L)and rapid response time(reaching 95%steady-state response within 3 s),when calibrating in glucose standard solution.In agricultural application,the as-prepared biosensor was employed to detect the glucose concentration of tomato and cucumber samples.The results showed that the relative deviation of this method was less than 5%when compared with that of high-performance liquid chromatography,implying high accuracy of the presented biosensor in glucose detection in plants.

Quantification of rhBMP2 in bioactive bone materials

Bone morphogenetic protein(BMP),belongs to transforming growth factor-b(TGF-b)superfamily except BMP-1.Implanting BMP into muscular tissues induces ectopic bone formation at the site of implantation,which provides opportunity for the treatment of bone defects.Recombinant human BMP-2(rhBMP-2)has been used clinically,but the lack of standard methods for quantifying rhBMP-2 biological activity greatly hindered the progress of commercialization.In this article,we describe an in vitro rhBMP-2 quantification method,as well as the data analyzation pipeline through logistic regression in RStudio.Previous studies indicated that alkaline phosphatase(ALP)activity of C2C12 cells was significantly increased when exposed to rhBMP-2,and showed dose-dependent effects in a certain concentration range of rhBMP-2.Thus,we chose to quantify ALP activity as an indicator of rhBMP-2 bioactivity in vitro.A sigmoid relationship between the ALP activity and concentration of rhBMP-2 was discovered.However,there are tons of regression models for such a non-linear relationship.It has always been a major concern for researchers to choose a proper model that not only fit data accurately,but also have parameters representing practical meanings.Therefore,to fit our rhBMP-2 quantification data,we applied two logistic regression models,three-parameter log-logistic model and four-parameter log-logistic model.The four-parameter log-logistic model(adj-R2>0.98)fits better than three-parameter log-logistic model(adj-R2>0.75)for the sigmoid curves.Overall,our results indicate rhBMP-2 quantification in vitro can be accomplished by detecting ALP activity and fitting four-parameter log-logistic model.Furthermore,we also provide a highly adaptable R script for any additional logistic models.

Immune risk assessment of residual αGal in xenogeneic decellularized cornea using GTKO mice

The xenogeneic decellularized corneal matrix(DCM)was expected to be used in lamellar keratoplasty in clinic as the substitute of allogeneic cornea.After decellularization treatment,the remaining risk of xenograft rejection needed to be assessed.The galactose-α1,3-galactose,as the most abundant and closely rejection-related xenogeneic antigen,should be one of the important factors concerned in immunological evaluation.In this study,residual αGal in the DCM was first determined by an enzyme-linked immunosorbent assay method with qualified accuracy and specificity.Then the DCM was implanted subcutaneously into the α1,3-galactosyltransferase gene-knockout(GTKO)mice,accompanied by the implantation in the wild-type C57BL/6 mice as a comparison.The total serum antibody levels,anti-Gal antibody levels,inflammatory cytokines and ratios of splenic lymphocyte subtypes were detected and the histopathological analysis of implants were performed to systematically evaluate the immune responses.The experimental result showed the fresh porcine corneal matrix samples had(9.90±1.54)×10^12 αGal epitope per mg while the content of residual aGal in the DCM was(7.90±2.00)×10^12 epitope per mg.The GTKO mice had similar potential of reaction to immune stimulation to that of wild-type C57BL/6 mice.At 4 weeks after implantation of DCM,in WT mice and GTKO mice there were both innate immunity response to the DCM characterized by macrophage infiltration.But the elevations of anti-Gal IgG level and the percentage of splenic natural killer cells were only detected in GTKO mice.These changes were thought to be pertinent to the residual αGal antigen,which could not be detected in WT mice.No further αGal antibody-mediated cellular immunity and significant changes of serum cytokine contents were found in GTKO mice,which perhaps suggested that the immune reactions to the DCM after 4 weeks of implantation were moderate and had minor effect on the survival of the corneal graft.

Surgical staples:Current state-of-the-art and future prospective

Wound closing is one of the widely performed and prominent clinical practices in the surgical intervention process.A physician or surgeon has several options ranging from surgical sutures and adhesive strips to fibrin glue for effective wound closure to close the commonly occurring surgical cuts and deep skin tissue injuries.However,all the commercially available wound closure devices have some limitations in each and another perspective.From the beginning of the late 90s,surgical staples got tremendous attention as efficient wound closure devices for their time-effective and sufficient mechanical strength,performance feasibility,fewer chances of surgical site infection and require minimal expertise characteristics in consideration of remote location.Even in the context of the recent COVID19 pandemic,the clinical acceptance and patient compliance for the staples have increased due to minimizing the chances of prolonged interaction between the patient and physicians.The surgical staples application is extensive and diversified,ranging from common external cuts to highly complex surgery procedures like laparoscopic appendectomy,intestinal anastomosis,etc.Thus,in this literature review,we try to give a comprehensive glimpse of the development and current state-of-the-art surgical staples in consideration with research from a commercial point of view.On a special note,this review also describes a very brief outline of the regulatory aspects and some common internationally acceptable‘de jure standards for the development of commercially viable surgical staples.

An effective method to generate controllable levels of ROS for the enhancement of HUVEC proliferation using a chlorin e6-immobilized PET film as a photo-functional biomaterial

Reactive oxygen species(ROS)are byproducts of cellular metabolism;they play a significant role as secondary messengers in cell signaling.In cells,high concentrations of ROS induce apoptosis,senescence,and contact inhibition,while low concentrations of ROS result in angiogenesis,proliferation,and cytoskeleton remodeling.Thus,controlling ROS generation is an important factor in cell biology.We designed a chlorin e6(Ce6)-immobilized polyethylene terephthalate(PET)film(Ce6-PET)to produce extracellular ROS under red-light irradiation.The application of Ce6-PET films can regulate the generation of ROS by altering the intensity of light-emitting diode sources.We confirmed that the Ce6-PET film could effectively promote cell growth under irradiation at 500 μW/cm^(2) for 30 min in human umbilical vein endothelial cells.We also found that the Ce6-PET film is more efficient in generating ROS than a Ce6-incorporated polyurethane film under the same conditions.Ce6-PET fabrication shows promise for improving the localized delivery of extracellular ROS and regulating ROS formation through the optimization of irradiation intensity.

A versatile approach for temporary storage and shipping of in vitro cultured cells,cell sheets and tissue engineered constructs-a preliminary report

Temporary storage/shipping of cell/tissue engineering products from bench to bedside is a key aspect of re-generative medicine.The current proof-of-concept study presents a multipurpose device for temporary storage/shipping of cell culture dishes containing cell/tissue constructs.The device,made with readily available raw ma-terials,contains three elements viz.a specialized lid,polymeric plates having grooves and a set of nuts and bolts.As part of the performance evaluation,the device was first subjected to a simulated storage/shipping process,wherein the leak-proof and aseptic containment of the contents was demonstrated.Subsequently,the setup was used for temporary storage/shipping of dishes having(a)L929 cell monolayers cultured on treated surfaces,(b)SIRC,HaCaT and A549 cell sheets cultured on thermo-responsive surfaces,(c)HOS-cell encapsulated agar gels and(d)HOS-cell seeded silk fibroin mats.The results showed that the health of cell monolayers/cell sheets/tissue constructs after the process was comparable to that before the process.The device was scalable,simple to handle,can be made for a single or multi-use purpose,and can be resizable to load other culture vessels.The design of the storage/shipping device described in this report thus offers versatile features and applications.

Natural Biopolymers for Bone Tissue Engineering:A Brief Review

Tissue engineering is a well-proven technique for the creation of functional alternatives for regenerative medicine and plays a critical role in patient treatment.Several natural-origin biopolymers such as chitosan,hyaluronic acid,gelatin,collagen,etc.are extensively explored for various biomedical applications.Among,these polymers are exclusively investigated in tissue engineering applications due to their highly favorable properties,such as high biocompatibility,slow degradation,mechanical tenability,structural similarity with native tissues,bioactivity,etc.The present review summarizes the recent advances of biopolymers in bone tissue engineering It also covers the topic of natural polymer modification to achieve superior characteristics primarily mechanical properties towards bone regeneration and discussed the best methods for dealing with them.Therefore,the review can drive the development of biomimetic materials for futuristic applications.

Update on oral and oropharyngeal cancer staging-International perspectives

Squamous cell carcinoma of the oral cavity and oropharynx have been used synonymously and interchangeably in the world literature in the context of head and neck cancers.As the 21st century progresses,divergence between the two have become more evident,particularly due to evidence related to human papillomavirus-associated oropharyngeal squamous cell carcinoma.As such,the American Joint Committee on Cancer recently published the 8th edition Cancer Staging Manual,serving as a continued global resource to clinicians and researchers.Through changes in staging related to T and N clinical and pathologic classifications,the new system is expected to influence current management guidelines of these cancers that have distinct anatomic and etiopathogenic characteristics.This article aims to review such impactful changes in a time of critical transition of the staging of head and neck cancer and how these changes may affect clinicians and researchers worldwide.