Biomedical Technology最新文献

Micro-nano hydrogel is a novel functional material that has attracted extensive attention in various fields. Due to the size of micron and nano level, high water content and high specific surface area, the micro-nano hydrogels can achieve minimally invasive repair and are considered as promising agents in tissue repair engineering. In this review, we summarize the design and development of micro-nano hydrogels for biomedical applications, first introduce biopolymers for the synthesis of hydrogels, then introduce the preparation technologies of microgels and nanogels respectively, and systematically summarize the application characteristics and forms of different preparation technologies. Finally, the latest application progresses of microgels in local drug delivery, bone tissue repair, soft tissue repair and immunomodulation are introduced in detail, as well as the latest application progress of nanohydrogels in cartilage repair, antibacterial, antitumor/cancer nerve repair and prevention and diagnosis of diseases, and the key research directions of micro-nano hydrogel preparation technologies in the future are clarified.

Self-healing hydrogels are promising biomedical materials owing to their ability to restore the structure fracture and regain the initial functions. However, a comprehensive review of the dynamic hydrogels based on the Knoevenagel Condensation (KC) for wound healing is yet lacking. Here, we first summarize the recent advances in self-healing hydrogels constructed by the KC reaction, and then systematically illustrate the reaction process and self-healing mechanisms. The features of these hydrogels, for instance, self-healing characteristics, injectability, thermosensitivity, as well as thermoplastic properties are also highlighted. In addition, a series of hydrogels constructed by this reaction in the presence of various catalysts are presented and discussed. Furthermore, the potential application within the rapidly expanding field of wound healing is discussed in detail. Finally, recommendations to guide the designing strategies and a perspective on challenges faced by this kind of hydrogels are also described.

Platinum drugs have been coined as one of the great success representatives in cancer chemotherapy. With the accidental discovery of cisplatin, thousands of platinum-based complexes have been synthesized, including clinically approved classical platinum(II) (Pt(II)) drugs, non-classical Pt(II) drugs, and platinum(IV) (Pt(IV)) drugs. Currently, these drugs are widely utilized in the treatment of various solid tumors in the clinic. Unfortunately, systemic toxicity and innate or acquired drug resistance greatly restrict their applications. The nanocarrier-based drug delivery systems (NDDSs) offer the possibility of targeted delivery of platinum drugs to the tumor tissue with reduced toxicity and enhanced drug efficacy. Thus, in this review, inorganic and organic nanocarriers for platinum drug delivery are introduced. The significant improvements, future challenges, and prospects of the nanocarriers toward potential clinical application are briefly discussed.

Oral antibiotics have served as a primary strategy for bacterial infection. However, the increasingly prominent issues including antibiotics resistance and intestinal dysbiosis sounded the alarm to this traditional administration strategy. Herein, we summarize the state-of-the-art advances in the delivery of oral antibiotics. In this review, the emergency of bacterial infection and the effect of excessive antibiotics are discussed at first. Then, current attempts to prevent microflorae from resistance and dysbiosis are briefly enumerated, including oral co-administration systems (like protectors, adsorbents, activity enhancers, etc.) and nanoparticle-based delivery systems. Moreover, we also briefly introduce the development of mimetic antibiotics based on metal particles and highlight a novel micelle nanoparticle system, which possesses a positive charge and glucosylated surface to achieve targeted treatment. We strongly believe such an ingenious design could be applied in more scenarios for oral antibiotics delivery. Ultimately, we also put forward a concise summary and perspective of this field.

Flexible electronics are attracting considerable attention due to their promising performance including conductivity, stain- or pressure-sensing performance, skin-affinity, flexibility, etc. In particular, the structural design has promoted their properties and brought advanced functions, which make them valuable in biomedical applications including health monitoring, therapeutic applications and implantable devices. Herein, a review on the recent progress of flexible electronics with micro-/nano-structures is provided, involving the manufacturing technologies and applications in biomedical fields. Following these two sections, remaining challenges and the perspectives on future directions are also proposed.

The traditional membrane with single structure cannot satisfy complex clinical applications. Inspired by lotus leaf, a novel structure Janus membrane has achieved more attention recently. Janus membrane is a membrane structure which has two faces with opposite properties. This special structure endows it with asymmetric surface wettability, which can provide an intrinsic driving force to transport along a specified direction, thus achieve unidirectional liquid transport and selective liquid separation. Janus membrane has a promising future, and has been widely used in chemical fields such as self-cleaning, oil/water separation, mist collection, and desalination, while less studied in biomedical field. In this review, the biomedical applications especially in different stages of wound healing process, current challenges in fabrication process and future perspectives of Janus membranes in practical applications under different Janus models, such as hemostasis, bone regeneration, blood cell isolation and gastric mycosal defect will be discussed. It is expected that this unique structure can provide a good therapy prospect in biomedical fields.

Background

Liver fibrosis is recognized as a consequence of persistent liver damage. Hence, understanding the mechanisms of liver fibrosis could help patients reverse this process. Aggrephagy is a selective type of autophagy which is under study in various diseases. However, the investigation of aggrephagy in liver fibrosis has not been reported yet.

Methods

Five GEO databases were first batched into an integrated dataset by PCA analysis and facilitated for exploration of the aggrephagy-related genes. In addition, the diagnostic model under the aggrephagy-related genes was constructed by random forest. Then Western blot and immunofluorescence were employed in cells treated by autophagy-inhibitor Bafilomycin A1 to analyze whether the aggrephagy induced by liver fibrosis is necessary for aggregates degradation. Furthermore, the single cell data from GEO database and AUCell analysis functioned to detect the aggrephagy score. CellChat analysis compared the interaction strength and underlying receptor ligands between the different aggrephagy score groups. Furthermore, we used the monocle function to display the dynamic process from low aggrephagy score to high aggrephagy score groups. Finally, we used the consensus cluster to compare the clinical characteristics and underlying drug compounds under aggrephagy-score.

Results

First, we observed that aggrephagy score was much higher in the liver fibrosis group than in the normal group. Then our results showed that aggrephagy score was positively correlated with several metabolism pathways. In addition, aggrephagy related diagnostic model showed higher efficiency than other markers of liver fibrosis. Further experiments revealed that the removal of aggregates in liver fibrosis was depended on aggrephagy. We then observed that aggrephagy score and CFTR levels were dominantly located in hepatocytes from single-cell data. Moreover, the high aggrephagy-score group showed increased cell interaction strength, intercellular receptor-ligand signaling, and the transcription factor activity of HNF1B than the low aggrephagy-score groups. Hence, aggrephagy might be a promising target for liver fibrosis.

Conclusions

Our results showed that the aggrephagy score is a promising index for diagnosing liver fibrosis.

Background

Extracellular matrix (ECM) acts as a physical barrier to tumors, resulting in the lysis or delay of drug delivery. Integrins (ITGs) are essential for tumor cell-ECM interactions. Thus, we established a novel prognostic model to predict overall survival, immunotherapy benefits, and therapeutic agents in gastric cancer (GC) based on ITGs-related ECM landscape.

Methods

Using the TCGA-STAD dataset, we studied the genetic and transcriptional changes of ITGs. We used a merged cohort for ITGs survival analysis and determined molecular pattern clusters using consensus unsupervised clustering methodology. We confirmed the distinct ECM landscape between constructed clusters by performing gene set variation and Kaplan-Meier analysis. We utilized prognostic differentially expressed genes between clusters to develop a prognostic model utilizing logistic least absolute shrinkage and selection operator cox regression analysis, followed by stepwise multivariate Cox analysis in the training dataset. The model was validated by receiver operating characteristic curves and Kaplan-Meier analysis in the testing dataset and seven validation datasets. We compared our model to 35 previously published models. To analyze immune infiltration, we used multiple algorithms, which were further confirmed by single-cell RNA-sequencing and fluorescent multiplex immunohistochemistry. We explored tumor mutation burden (TMB), microsatellite instability-high (MSI-H) grade, immunotherapy response, chemotherapy sensitivity, and clinical significance between the low-risk and high-risk groups. Finally, we assessed the risk score in five reported molecular subtypes.

Results

The two ITGs-related clusters were identified, and their ECM landscapes were distinct. The prognostic model was constructed and had shown stable performance in internal and external validation. In addition, our model outperformed 35 previously published models. High-risk patients had a bad prognostic ECM landscape, high stromal cell inflammation, a lower TMB, a lower MSI-H grade, a worse tumor stage, a worse response to immunotherapy, and less sensitivity to chemotherapy. In five reported molecular subtypes, the worse subtypes showed a higher risk score.

Conclusions

The prognostic model could be an effective and promising tool for predicting prognosis and therapy response in GC patients.

As an emerging technology relevant to materials science, 3D printing technology simplifies material production process, shortens the preparation cycle, and provides a broader space for disease treatment. This review introduces the latest development in 3D printing, the goal is showing summary of the preparation and the utilization of this technology. We first describe the familiar biological ink for 3d printing. Then, we focus on different applications, including drug delivery, tumor modeling, and organ printing. Later, we described the application of this technology in some disciplines, including neurosurgery, gastrointestinal surgery, and orthopedics. Finally, the recent challenges and prospects of 3D printing are presented.

Nucleic acid amplification techniques are broadly employed in nucleic acid testing due to their efficient accumulation of nucleic acid sequences. With the development of biotechnology, they are further applied to proteins, living cells, extracellular vesicles (EVs) and even small molecule detection to amplify detection signals for ultra-sensitive bioanalysis. As important amplification techniques, isothermal amplification techniques, CRISPR/Cas system, DNA Walker and DNAzymes are playing an increasingly important role in signal magnification. Cooperating with functional nanomaterials, they present a wide availability in biosensing and bioimaging. This review gives a comprehensive summary of the four main signal amplification techniques mentioned above and their applications in biosensing and bioimaging. Finally, some of the challenges and further opportunities of nucleic acid amplification strategy in the current biomedical technology field are discussed.