A hydrodynamic-based dual-function microfluidic chip for high throughput discriminating tumor cells.

A hydrodynamic-based microfluidic chip consisted of two function units that could not only separate tumor cells (TCs) from whole blood but also remove residual blood cells was designed. The separation of TCs was achieved by a straight contraction-expansion array (CEA) microchannel on the front end of the chip. The addition of contractive structure brought a micro-vortex like Dean vortex that promoted cell focusing in the channel, while when cells entered the dilated region, the wall-induced lift force generated by the channel wall gave cells a push away from the wall. As the wall-induced lift force is proportional to the third power of the cell diameter, TCs with larger diameter will have a larger lateral migration under the wall-induced lift force, realizing the separation of TCs from blood sample. Fluorescent particles with diameters of 19.3 µm and 4.5 µm were used to simulate TCs and red blood cells, respectively, to verify the separation capacity of the proposed CEA microchannel for particles with different diameter. And a separation efficiency 98.7% for 19.3 µm particles and a removal rate 96.2% for 4.5 µm particles was observed at sample flow rate of 10 µL min-1 and sheath flow rate of 190 µL min-1. In addition, a separation efficiency about 96.1% for MCF-7 cells (stained with DiI) and removal rates of 96.2% for red blood cells (RBCs) and 98.7% for white blood cells (WBCs) were also obtained under the same condition. However, on account of the large number of blood cells in the blood, there will be a large number of blood cells remained in the isolated TCs, so a purification unit based on hydrodynamic filtration (HDF) was added after the separation microchannel. The purification channel is a size-dictated cell filter that can remove residual blood cells but retain TCs, thus achieving the purification of TCs. Combined the CEA microchannel and the purifier, the microchip facilitates sorting of MCF-7 cells from whole blood with a separation rate about 95.3% and a removal rate over 99.99% for blood cells at a sample flow rate of 10 µL min-1, sheath flow rate of 190 µL min-1 and washing flow rate of 63 µL min-1.

The role of dermal fibroblasts in autoimmune skin diseases.

Fibroblasts are an important subset of mesenchymal cells in maintaining skin homeostasis and resisting harmful stimuli. Meanwhile, fibroblasts modulate immune cell function by secreting cytokines, thereby implicating their involvement in various dermatological conditions such as psoriasis, vitiligo, and atopic dermatitis. Recently, variations in the subtypes of fibroblasts and their expression profiles have been identified in these prevalent autoimmune skin diseases, implying that fibroblasts may exhibit distinct functionalities across different diseases. In this review, from the perspective of their fundamental functions and remarkable heterogeneity, we have comprehensively collected evidence on the role of fibroblasts and their distinct subpopulations in psoriasis, vitiligo, atopic dermatitis, and scleroderma. Importantly, these findings hold promise for guiding future research directions and identifying novel therapeutic targets for treating these diseases.

A Portable Microplasma Optical Emission Spectrometric Device with Online Digestion Function for Field and Sensitive Determination of Lead in Biological Samples.

Accurate detection and screening of Pb in biological samples is helpful to assess the risk associated with lead pollution to human health. However, conventional atomic spectroscopic instruments are bulky and cumbersome, requiring additional sample pretreatment equipment, and difficult to perform field analysis with. Herein, a portable point discharge (PD) microplasma-optical emission spectrometric (OES) device with online digestion function is designed for field and sensitive determination of lead in biological samples. With rice as a model, online digestion of a batch of six 50 mg samples can be achieved in the HNO3 and H2O2 system within 25 min by a temperature control and timing module. Compared to the conventional microwave digestion, the digestion efficiency of this device reaches 97%. Pb in digestion solution is converted into volatile species by hydride generation (HG) and directly introduced into PD-OES for excitation and detection by a self-designed rotatable and telescopic cutoff gas sampling column. Six samples can be successively detected in 2 min, and argon consumption of the whole process is only <800 mL. Under the optimized conditions, the detection limit of Pb is 0.018 mg kg-1 (0.9 µg L-1) and precision is 3.6%. The accuracy and practicability of the present device are verified by measuring several certified reference materials and real biological samples. By virtue of small size (23.5 × 17 × 8.5 cm3), lightweight (2.5 kg), and low energy consumption (24.3 W), the present device provides a convenient tool for field analysis of toxic elements in biological samples.

Animal models of eosinophilic esophagitis, review and perspectives.

Eosinophilic oesophagitis (EoE) is an allergen/immune-mediated chronic esophageal disease characterized by esophageal mucosal eosinophilic infiltration and esophageal dysfunction. Although the disease was originally attributed to a delayed allergic reaction to allergens and a Th2-type immune response, the exact pathogenesis is complex, and the efficacy of existing treatments is unsatisfactory. Therefore, the study of the pathophysiological process of EOE has received increasing attention. Animal models have been used extensively to study the molecular mechanism of EOE pathogenesis and also provide a preclinical platform for human clinical intervention studies of novel therapeutic agents. To maximize the use of existing animal models of EOE, it is important to understand the advantages or limitations of each modeling approach. This paper systematically describes the selection of experimental animals, types of allergens, and methods of sensitization and excitation during the preparation of animal models of EoE. It also discusses the utility and shortcomings of each model with the aim of providing the latest perspectives on EoE models and leading to better choices of animal models.

Exosomes containing miR-1469 regulate natural killer cells by targeting CD122 in non-segmental vitiligo.

BACKGROUND: Plasma exosomal microRNAs (miRNAs) have been used as potential biomarkers for various diseases and have been investigated for their possible involvement in the pathogenesis of vitiligo. However, the miRNA expression profile of plasma exosomes in patients with non-segmental vitiligo (NSV) has not been determined yet. OBJECTIVE: To screen differentially expressed microRNAs in plasma exosomes derived from patients with NSV and explore their roles in the pathogenesis of NSV. METHODS: High-throughput sequencing was performed to determine the expression profiles of exosomal miRNAs in NSV. The effect of upregulated miR-1469 in NSV circulating exosomes on natural killer (NK) cells was further investigated using various molecular biological techniques. RESULTS: MiR-1469 was identified as a candidate biomarker whose expression was significantly increased in circulating exosomes of NSV patients. Circulating exosomes were internalized by NK cells and increased NK cell proliferation viability and IFN-γ secretion capacity delivering miR-1469. Further studies revealed that the upregulation of CD122, the predicted target of miR-1469, could partially reverse the effect of miR-1469 on natural killer cells. CONCLUSION: Alterations in plasma exosomal cargo occur in NSV and appear to contribute to NK cell dysfunction. Exosomal miR-1469 may be a biomarker of disease activity and could be used as a therapeutic drug target against innate immunity in NSV patients. The present study provides new insights into the role of exosomal miRNAs in NSV and suggests a novel miR-1469-CD122-IFN-γ pathway of NK cell underlying pathogenesis of NSV.

Tracking and imaging nano-plastics in fresh plant using cryogenic laser ablation inductively coupled plasma mass spectrometry.

Tracking and imaging of nano-plastics are extremely challenging, especially in fresh biological samples. Here, we propose a new strategy in which polystyrene (PS) was doped with the europium chelate Eu (DBM)3bpy to quantify, track, and in situ image nano-plastics in fresh cucumber based on inherent metals using cryogenic laser ablation inductively coupled plasma mass spectrometry (cryo-LA-ICP-MS). The cryogenic conditions provide a stable condition for imaging fresh cucumber, suppressing the evaporation of water in fresh plants, and maintaining the original structure of plants with respect to room temperature imaging in LA-ICP-MS. The plants were cultivated in two types of nano-plastics solutions with low (50 mg/L) and high (200 mg/L) concentrations for 9 days. The results showed that nano-plastics mainly enrich the roots and have negative effects, which decrease the trace elements of Zn, Mn, and Cu in cucumber. Smaller PS particles are able to penetrate the plant more easily and inflict serious damage. Novel imaging method provides a novel insight into the tracking and imaging of nano-plastics in fresh plant samples. The results illustrated that nano-plastics deposition on plants has the potential to have direct ecological effects as well as consequences for potential health.

Exosomal miRNAs in autoimmune skin diseases.

Exosomes, bilaterally phospholipid-coated small vesicles, are produced and released by nearly all cells, which comprise diverse biological macromolecules, including proteins, DNA, RNA, and others, that participate in the regulation of their biological functions. An increasing number of studies have revealed that the contents of exosomes, particularly microRNA(miRNA), play a significant role in the pathogenesis of various diseases, including autoimmune skin diseases. MiRNA is a class of single-stranded non-coding RNA molecules that possess approximately 22 nucleotides in length with the capability of binding to the untranslated as well as coding regions of target mRNA to regulate gene expression precisely at the post-transcriptional level. Various exosomal miRNAs have been found to be significantly expressed in some autoimmune skin diseases and involved in the pathogenesis of conditions via regulating the secretion of crucial pathogenic cytokines and the direction of immune cell differentiation. Thus, exosomal miRNAs might be promising biomarkers for monitoring disease progression, relapse and reflection to treatment based on their functions and changes. This review summarized the current studies on exosomal miRNAs in several common autoimmune skin diseases, aiming to dissect the underlying mechanism from a new perspective, seek novel biomarkers for disease monitoring and lay the foundation for developing innovative target therapy in the future.

1,25-Dihydroxyvitamin D3 Provides Benefits in Vitiligo Based on Modulation of CD8+ T Cell Glycolysis and Function.

Vitiligo is a common autoimmune skin disease caused by autoreactive CD8+ T cells. The diverse effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on immune cell metabolism and proliferation have made it an interesting candidate as a supporting therapeutic option in various autoimmune diseases. This study aimed to elucidate the immunomodulatory effects of 1,25(OH)2D3 in vitiligo. Cross-sectional relationships between serum 1,25(OH)2D3 levels and disease characteristics were investigated in 327 patients with vitiligo. The immunomodulatory and therapeutic effects of 1,25(OH)2D3 were then investigated in vivo and in vitro, respectively. We found that 1,25(OH)2D3 deficiency was associated with hyperactivity of CD8+ T cells in the vitiligo cohort. In addition, 1,25(OH)2D3 suppressed glycolysis by activating the AMP-activated protein kinase (AMPK) signaling pathway, thereby inhibiting the proliferation, cytotoxicity and aberrant activation of CD8+ T cells. Finally, the in vivo administration of 1,25(OH)2D3 to melanocyte-associated vitiligo (MAV) mice reduced the infiltration and function of CD8+ T cells and promoted repigmentation. In conclusion, 1,25(OH)2D3 may serve as an essential biomarker of the progression and severity of vitiligo. The modulation of autoreactive CD8+ T cell function and glycolysis by 1,25(OH)2D3 may be a novel approach for treating vitiligo.

Interaction of Cellular Uptake of Nanosilver and Metallothionein Stress Expression Elucidated by 2D Single-Cell Analyses Based on LIF and ICP-MS.

The exploration of cytology mechanisms of nanosilver uptake, toxicity, and detoxification has become an important issue due to its widespread applications. Previous studies have shown differences in the toxic response of mammalian cells to nanosilver. However, the analysis results based on cell populations ignore the impact of cell uptake heterogeneity on the expression of associated stress proteins and cellular physiological activities. In this respect, this work investigated the interaction between silver uptake and metallothionein (MT) expression in individual cells. In addition, we have also preliminarily elucidated the sensitivity variation to AgNPs by using five cell lines, e.g., LX-2, HepG-2, SK-HEP-1, Huh-7, and MDA-MB-231, by adopting a two-dimensional (2D) high-throughput single-cell analysis platform coupling laser-induced fluorescence (LIF) and inductively coupled plasma mass spectrometry (ICP-MS). We developed a 2D data analysis method for one-to-one unification of fluorescence-mass spectrometry signals corresponding to a specific single cell. It indicated that there is no obvious correlation between cellular silver uptake and cell size, and the low MT expression of cells is more sensitive to silver nanoparticles. For each cell line, significant heterogeneity in MT expression was observed. This provides important information for understanding the potential heterogeneous effects of nanosilver on mammalian biological systems. Overall, detoxified cells are more tolerant to nanosilver and normal cells are more tolerant than cancer cells.

Artificial intelligence and machine learning in aneurysmal subarachnoid hemorrhage: Future promises, perils, and practicalities.

INTRODUCTION: Aneurysmal subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke with thirty-day mortality as high as 40%. Given the expansion of Machine Learning (ML) and Artificial intelligence (AI) methods in health care, SAH patients desperately need an integrated AI system that detects, segments, and supports clinical decisions based on presentation and severity. OBJECTIVES: This review aims to synthesize the current state of the art of AI and ML tools for the management of SAH patients alongside providing an up-to-date account of future horizons in patient care. METHODS: We performed a systematic review through various databases such as Cochrane Central Register of Controlled Trials, MEDLINE, Scopus, Cochrane Database of Systematic Reviews, and Embase. RESULTS: A total of 507 articles were identified. Following extensive revision, only 21 articles were relevant. Two studies reported improved mortality prediction using Glasgow Coma Scale and biomarkers such as Neutrophil to Lymphocyte Ratio and glucose. One study reported that ffANN is equal to the SAHIT and VASOGRADE scores. One study reported that metabolic biomarkers Ornithine, Symmetric Dimethylarginine, and Dimethylguanidine Valeric acid were associated with poor outcomes. Nine studies reported improved prediction of complications and reduction in latency until intervention using clinical scores and imaging. Four studies reported accurate prediction of aneurysmal rupture based on size, shape, and CNN. One study reported AI-assisted Robotic Transcranial Doppler as a substitute for clinicians. CONCLUSION: AI/ML technologies possess tremendous potential in accelerating SAH systems-of-care. Keeping abreast of developments is vital in advancing timely interventions for critical diseases.

Comparison of Pivot Profile (PP), Rate-All-That-Apply (RATA), and Pivot-CATA for the sensory profiling of commercial Chinese tea products.

Rapid sensory profiling methods relying on consumers' perceptions are getting prevalent and broadly utilized by labs and companies to supersede conventional sensory profiling methodologies. Till now, various intensity-based sensory methods such as the newly proposed Pivot-Check-All-That-Apply (CATA) are limitedly developed and compared. In this investigation, Pivot Profile (PP), Rate-All-That-Apply (RATA), and Pivot-CATA methods were applied and validated using tea consumers and commercial Chinese tea products as samples. Data from three approaches were collected, analyzed by correspondence analysis (CA), and used to compare the three methods assessing the panel assessment process, sensory maps, confidence ellipses, and practical applications. Pivot-CATA exhibited a high similarity with RATA (RV = 0.873), and a lower similarity with PP (RV = 0.629). Of the three intensity-related methods, confidence ellipses on the RATA sensory map were the smallest and overlapped the least. However, Pivot-CATA consumed less time in collecting data and its questionnaire was more friendly to participants compared with PP and made the difference in intensity of samples more noticeable to the participants than RATA due to the existence of the pivot sample. Its experimental versatility also allows for a wide range of applications, indicating that the Pivot-CATA is an approach with great promise for routine use.

Single Cell Phenotypic Analysis for Cancer Stem Cell Identification by Dual-Isotope ICP-QMS.

Single cell phenotypic analysis is significant for clinical diagnosis, treatment, and prognosis of cancer. Accurate differentiation of cancer stem cell (CSC) subpopulations from a large number of cancer cells may become a cancer surveillance tool and provide important implications for the development of new CSC-targeted therapy strategies. Herein, we report a new approach based on dual-isotope inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) for single cell phenotypic analysis. High-throughput single cell sampling was achieved by a spiral channel microfluidic chip for cell focusing and alignment, and single cell analysis was performed with time-resolved ICP-QMS by identifying the highly specific probes. This enables the monitoring of two surface protein markers (EpCAM and MUC1) of three cell types, i.e., HeLa, MCF-7, and HepG2, at single cell level. The analysis of breast cancer stem cells further confirmed its capability in distinguishing rare cell phenotypes. The present study provides promising possibilities for adopting ICP-QMS in biomedical investigations in terms of cell typing, stemness identification of tumor cells, and cell heterogeneity analysis.

[Corona virus disease 2019 lesion segmentation network based on an adaptive joint loss function].

Corona virus disease 2019 (COVID-19) is an acute respiratory infectious disease with strong contagiousness, strong variability, and long incubation period. The probability of misdiagnosis and missed diagnosis can be significantly decreased with the use of automatic segmentation of COVID-19 lesions based on computed tomography images, which helps doctors in rapid diagnosis and precise treatment. This paper introduced the level set generalized Dice loss function (LGDL) in conjunction with the level set segmentation method based on COVID-19 lesion segmentation network and proposed a dual-path COVID-19 lesion segmentation network (Dual-SAUNet++) to address the pain points such as the complex symptoms of COVID-19 and the blurred boundaries that are challenging to segment. LGDL is an adaptive weight joint loss obtained by combining the generalized Dice loss of the mask path and the mean square error of the level set path. On the test set, the model achieved Dice similarity coefficient of (87.81 ± 10.86)%, intersection over union of (79.20 ± 14.58)%, sensitivity of (94.18 ± 13.56)%, specificity of (99.83 ± 0.43)% and Hausdorff distance of 18.29 ± 31.48 mm. Studies indicated that Dual-SAUNet++ has a great anti-noise capability and it can segment multi-scale lesions while simultaneously focusing on their area and border information. The method proposed in this paper assists doctors in judging the severity of COVID-19 infection by accurately segmenting the lesion, and provides a reliable basis for subsequent clinical treatment.

Two-Dimensional Multi-parameter Cytometry Platform for Single-Cell Analysis.

A 2D flow cytometry platform, known as CytoLM Plus, was developed for multi-parameter single-cell analysis. Single particles or cells after hydrodynamic alignment in a microfluidic unit undergo first-dimension fluorescence and side scattering dual-channel optical detection. They were thereafter immediately directed to ICP-MS by connecting the microfluidic unit with a high-efficiency nebulizer to facilitate the second-dimension ICP-MS detection. Flow cytometry measurements of fluorescent microspheres evaluated the performance of CytoLM Plus for optical detection. 6434 fluorescence bursts were observed with a valid signal proportion as high as 99.7%. After signal unification and gating analysis, 6067 sets of single-particle signals were obtained with 6.6 and 6.2% deviations for fluorescence burst area and height, respectively. This is fairly comparable with that achieved by a commercial flow cytometer. Afterward, CytoLM Plus was evaluated by 2D flow cytometry measurement of Ag+-incubated and AO-stained MCF-7 cells. A program for 2D single-cell signal unification was developed based on the algorithm of screening in lag time window. In the present case, a lag time window of -4.2 ± 0.09 s was determined by cross-correlation analysis and two-parameter optimization, which efficiently unified the concurrent single-cell signals from fluorescence, side scattering, and ICP-MS. A total of 495 sets of concurrent 2D signals were screened out, and the statistical analysis of these single-cell signals ensured 2D multi-parameter single-cell analysis and data elucidation.

Effects of a false-positive result in newborn congenital hypothyroidism screening on parents in Guangxi, China.

Background: As more than 500,000 neonates participate in newborn congenital hypothyroidism (CH) screening in Guangxi Zhuang Autonomous Region each year, the overall number of false-positive (FP) cases has increased. We aim to assess the parental stress in parents of neonates with FP CH results in Guangxi, find out the influence factors related to demographics, and provide the basis for personalized health education. Methods: The parents of neonates with FP CH results were invited to participate in the FP group, and the parents of neonates with all negative results were invited to participate in the control group. The parents completed a questionnaire on demographics, knowledge of CH, and the parental stress index (PSI) in the hospital for the first time. The follow-up visits for PSI were conducted 3, 6, and 12 months afterward through telephone and online. Results: A total of 258 and 1,040 parents participated in the FP and control groups, respectively. The parents in the FP group had better knowledge of CH and higher PSI scores than the parents in the control group. The result of logistic regression showed that the major influence factors related to the knowledge of CH were FP experience and source of knowledge. The parents in the FP group who were well-informed during the recall phone call had lower PSI scores than the other parents. The parents in the FP group showed decreasing PSI scores gradually in follow-up visits. Conclusion: The results suggested that FP screening results may affect parental stress and parent-child relationship. FP results increased the stress on the parents and increased their knowledge of CH passively.

Validation of a novel nutrition risk screening tool in stroke patients.

BACKGROUND AND OBJECTIVES: We aimed to apply a novel nutrition screening tool to stroke patients and assess its reliability and validity. METHODS AND STUDY DESIGN: Cross-sectional data among 214 imaging-confirmed stroke patients were collected between 2015 and 2017 in two public hospitals in Hebei, China. Delphi consultation was conducted to evaluate the items in the NRS-S scale. Anthropometric indices including body mass index (BMI), triceps skin fold thickness (TSF), upper arm circumference (AMC) and mid-arm muscle circumference (MAMC) were measured. Internal consistency reliability, test-retest reliability, construct validity and content validity were assessed. In order to estimate content validity, two rounds Delphi consultation of fifteen experts were conducted to evaluate the items in the Nutrition Risk Screening Scale for Stroke (NRS-S). RESULTS: High internal consistency was indicated by Cronbach's alpha of 0.632 and a split-half reliability of 0.629; test-retest reliability of NRS-S items ranged from 0.728 to 1.000 (p<0.0001), except for loss of appetite (0.436, p<0.001) and gastrointestinal symptoms (0.213, p=0.042). Content validity index of 0.89 indicated robust validity of the items. Regarding construct validity, the Kaiser-Meyer-Olkin value was 0.579, and the result of the Bartlett test of sphericity was 166.790 (p<0.001). Three factors were extracted by exploratory factor analysis, which contributed to 63.079% of the variance. Confirmatory factor analysis was performed on the questionnaire, finding the p-value of the model to be 0.321, indicating a high model fitting index. CONCLUSIONS: A novel stroke-specific nutritional risk screening tool demonstrated a relatively high reliability and validity in its clinical application.

Carbon Nanotubes as Carriers in Drug Delivery for Non-Small Cell Lung Cancer, Mechanistic Analysis of Their Carcinogenic Potential, Safety Profiling and Identification of Biomarkers.

Non-small cell lung cancer (NSCLC) is a global burden leading to millions of deaths worldwide every year. Nanomedicine refers to the use of materials at the nanoscale for drug delivery and subsequent therapeutic approaches in cancer. Carbon nanotubes (CNTs) are widely used as nanocarriers for therapeutic molecules such as plasmids, siRNAs, antisense agents, aptamers and molecules related to the immunotherapy for several cancers. They are usually functionalized and loaded with standard drug molecules to improve their therapeutic efficiency. Functionalization and drug loading possibly decrease the genotoxic and carcinogenic potential of CNTs. In addition, the targeted cytotoxic properties of the drug improve and undesired toxicity decreases after drug loading and/or conjugation with proteins, including antibodies. For intended drug delivery, a lysosomal pH of 5.5 is more suitable and effective for the slow and extended release of cytotoxic drugs than a physiological of pH 7.4. Remarkably, CNTs possess intrinsic antitumor properties and are usually internalized by endocytosis. After being internalized, several mechanisms are involved in the therapeutic and carcinogenic effects of CNTs. They are generally safe for therapy, and their toxicity profile remains dependent on their physicochemical properties. Moreover, the dose, route, duration of exposure, surface properties and degradative potential determine the toxicity outcomes of CNTs locally or systemically. In summary, the use of CNTs in drug delivery and NSCLC therapy, as well as their genotoxic and carcinogenic potential and the possible mechanisms, has been discussed in this review. The therapeutic index is generally high for NSCLC cells treated with drug-loaded CNTs; therefore, they are effective carriers in implementing targeted therapy for NSCLC.

ROS-activatable biomimetic interface mediates in-situ bioenergetic remodeling of osteogenic cells for osteoporotic bone repair.

Bioenergy (ATP) is essentially required for supporting the osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs). However, factors such as high ROS levels and decreased glucose metabolism severely limit the bioenergy production in osteoporotic MSCs. We have prepared CaCO3-Quercetin- chromium (CaCO3-Qu-Cr) nanoparticles via ion coordination and packaged them into ROS-responsive gelatin/chitosan coating on titanium surface (Ti/Gel/CaCO3-Qu-Cr), aiming to improve the ATP production and cell mineralization by ameliorating ROS levels via Qu-mediated antioxidative effect and the promotional effect of Qu-Cr combination on glucose metabolism. Characterization results confirmed that Ti/Gel/CaCO3-Qu-Cr could be degraded in an ROS-responsive manner to release CaCO3-Qu-Cr nanoparticles continuously and eliminate excessive ROS in both the MSCs and microenvironment. Meanwhile, Ti/Gel/CaCO3-Qu-Cr significantly increased the glucose uptake and metabolism in osteoporotic MSCs and boosted their ATP and citrate production. This study laid the foundation for the development of functional titanium-based implants for the improvement of osteoporotic osseointegration.

Construction of Wogonin Nanoparticle-Containing Strontium-Doped Nanoporous Structure on Titanium Surface to Promote Osteoporosis Fracture Repair.

M2 polarization of macrophage is an important immunomodulatory event that attenuates inflammation. To regulate the immune microenvironment in osteoporotic conditions for enhancing bone healing, strontium-doped nano-structure is fabricated on the surface of titanium implant via microarc oxidation and electrochemical deposition technology, followed by the addition of multiplayer coatings embedded with silk fibroin-based wogonin nanoparticles (Ti-MAO/Sr/LBLWNP ) by layer-by-layer self-assembly technique (LBL). It is found that Ti-MAO/Sr/LBLWNP can release wogonin and Sr2+ in a sustainable manner for more than 7 and 21 days. In vitro studies show that Ti-MAO/Sr/LBLWNP significantly upregulates the expression of CD206 while reducing the expression of CD86. Meanwhile, Ti-MAO/Sr/LBLWNP can promote the expression level of M2 macrophage anti-inflammatory factor (TGF-ß1, Arg-1), which improves the proliferation and osteogenic differentiation of osteoblasts through paracrine signaling. Compared to bare titanium, Ti-MAO/Sr/LBLWNP significantly inhibits the expression of inflammatory factors around the implant and effectively promotes new bone formation at pre-implant interface after implantation for 4 weeks. This study provides a simple and effective method to develop functional titanium alloy materials for osteoporotic fracture repair.

Aptamer/Hydroxyapatite-Functionalized Titanium Substrate Promotes Implant Osseointegration via Recruiting Mesenchymal Stem Cells.

Endowing bone regeneration materials with both stem cell recruitment and osteoinduction properties is a key factor in promoting osseointegration of titanium (Ti) implants. In this study, Apt19s-grafted oxidized hyaluronic acid (OHA) was deposited onto a protein-mediated biomineralization hydroxyapatite (HAp) coating of Ti. HAp was achieved by the treatment of lysozyme and tris(2-carboxyethyl) phosphonate mixture and then soaked in calcium ion (Ca2+) solution to obtain functional Ti substrate (Ti/HAp/OHA-Apt). In vitro studies confirmed that Ti/HAp/OHA-Apt could effectively maintain the sustained release of Apt19s from Ti for 7 days. The released Apt19s significantly enhanced the migration of bone marrow mesenchymal stem cells (MSCs), which was reflected by the experiment of transwell assay, wound healing, and zymogram detection. Compared with pure Ti, Ti/HAp/OHA-Apt was able to adjust the adsorption of functional proteins at the Ti-based interface to expose their active sites, which significantly increased the expression of adhesion-associated proteins (vinculin and tensin) in MSCs to promote their adhesion on Ti-based interface. In vitro cell experiments of alkaline phosphatase activity staining, mineralization detection, and expression of osteogenesis-related genes showed that Ti/HAp/OHA-Apt significantly enhanced the osteogenic differentiation ability of MSCs, which may be highly related to the porous structure of hydroxyapatite on Ti interface. In vivo test of Micro-CT, H&E staining, and histochemical staining further confirmed that Ti/HAp/OHA-Apt was able to promote MSC recruitment at the peri-implant interface to form new bone. This work provides a new approach to develop functional Ti-based materials for bone defect repair.