Bioengineered Silk Protein-Based 3D In Vitro Models for Tissue Engineering and Drug Development: From Silk Matrix Properties to Biomedical Applications.

3D in vitro model has emerged as a valuable tool for studying tissue development, drug screening, and disease modeling. 3D systems can accurately replicate tissue microstructures and physiological features, mirroring the in vivo microenvironment departing from conventional 2D cell cultures. Various 3D in vitro models utilizing biomacromolecules like collagen and synthetic polymers have been developed to meet diverse research needs and address the complex challenges of contemporary research. Silk proteins, bearing structural and functional similarities to collagen, have been increasingly employed to construct advanced 3D in vitro systems, surpassing the limitations of 2D cultures. This review examines silk proteins' composition, structure, properties, and functions, elucidating their role in 3D in vitro models. Furthermore, recent advances in biomedical applications involving silk-based organoid models are discussed. In particular, the unique physiological attributes of silk matrix constituents in in vitro tissue constructs are highlighted, providing a meticulous evaluation of their importance. Additionally, it outlines the current research hurdles and complexities while contemplating future avenues, thereby paving the way for developing complex and biomimetic silk protein-based microtissues.

Aptamer-free upconversion nanoparticle/silk biosensor system for low-cost and highly sensitive detection of antibiotic residues.

The detection of antibiotics is crucial for safeguarding the environment, ensuring food safety, and promoting human health. However, developing a rapid, convenient, low-cost, and sensitive method for antibiotic detection presents significant challenges. Herein, an aptamer-free biosensor was successfully constructed using upconversion nanoparticles (UCNPs) coated with silk fibroin (SF), based on Förster resonance energy transfer (FRET) and the charge-transfer effect, for detecting roxithromycin (RXM). A synergistic FRET efficiency was achieved by utilizing alizarin red and RXM complexes as energy acceptors, with UCNP as the energy donor, and immobilizing an ultrathin SF protein corona within 10 nm. The biosensor detects RXM in deionized water with high sensitivity primarily through monolayer adsorption, with a detection range of 1.0 nM-141.6 nM and a detection limit as low as 0.68 nM. The performance of this biosensor was compared with the ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method for detecting antibiotics in river water separately and a strong correlation between the two methods was observed. The biosensor exhibited long-term stability in aqueous solutions (up to 60 d) with no attenuation of fluorescence intensity. Furthermore, the biosensor's applicability extended to the highly sensitive detection of other antibiotics, such as azithromycin. This study introduces a low-cost, eco-friendly, and highly sensitive method for antibiotic detection, with broad potential for future applications in environmental, healthcare, and food-related fields.

Design of Bombyx mori (B. mori) Silk Fibroin Microspheres for Developing Biosafe Sunscreen.

Sunscreens play a crucial role in protecting the skin from ultraviolet (UV) damage. However, present commercial sunscreens have a tendency to generate free radicals in the UV window, resulting in serious inflammatory responses and health problems. In this study, we demonstrate that silk fibroin microspheres (SFMPs) assembled from regenerated silk fibroin (SF) could scavenge free radicals while preventing UV irradiation and thus present a promising sunscreen. The SFMP reflected more UV light than SF and presented a higher stability than that of organic commercial sunscreens. In vitro analysis proved that SFMP could more efficiently scavenge the hydroxy radical and reduce the intracellular reactive oxygen than titanium dioxide (TiO2). In vivo experiments exhibited that SFMP provided stronger skin protection against UV irradiation than commercial sunscreens and TiO2. Furthermore, SFMP treatment significantly inhibited the skin inflammatory response. This work suggests that the SFMP has great potential to be developed into a biosafe sunscreen.

Injectable Bombyx mori (B. mori) silk fibroin/MXene conductive hydrogel for electrically stimulating neural stem cells into neurons for treating brain damage.

Brain damage is a common tissue damage caused by trauma or diseases, which can be life-threatening. Stem cell implantation is an emerging strategy treating brain damage. The stem cell is commonly embedded in a matrix material for implantation, which protects stem cell and induces cell differentiation. Cell differentiation induction by this material is decisive in the effectiveness of this treatment strategy. In this work, we present an injectable fibroin/MXene conductive hydrogel as stem cell carrier, which further enables in-vivo electrical stimulation upon stem cells implanted into damaged brain tissue. Cell differentiation characterization of stem cell showed high effectiveness of electrical stimulation in this system, which is comparable to pure conductive membrane. Axon growth density of the newly differentiated neurons increased by 290% and axon length by 320%. In addition, unfavored astrocyte differentiation is minimized. The therapeutic effect of this system is proved through traumatic brain injury model on rats. Combined with in vivo electrical stimulation, cavities formation is reduced after traumatic brain injury, and rat motor function recovery is significantly promoted.

Injectable Phage-Loaded Microparticles Effectively Release Phages to Kill Methicillin-Resistant Staphylococcus aureus.

The increasing prevalence of bacterial multidrug antibiotic resistance has led to a serious threat to public health, emphasizing the urgent need for alternative antibacterial therapeutics. Lytic phages, a class of viruses that selectively infect and kill bacteria, offer promising potential as alternatives to antibiotics. However, injectable carriers with a desired release profile remain to be developed to deliver them to infection sites. To address this challenge, phage-loaded microparticles (Phage-MPs) have been developed to deliver phages to the infection site and release phages for an optimal therapeutic effect. The Phage-MPs are synthesized by allowing phages to be electrostatically attached onto the porous polyethylenimine-modified silk fibroin microparticles (SF-MPs). The high specific surface area of SF-MPs allows them to efficiently load phages, reaching about 1.25 × 1010 pfu per mg of microparticles. The Phage-MPs could release phages in a controlled manner to achieve potent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Unlike the diffuse biodistribution of free phages post-intraperitoneal injection, Phage-MPs could continuously release phages to effectively boost the local phage concentration at the bacterial infection site after they are intraperitoneally injected into an abdominal MRSA-infected mouse model. In a mouse abdominal MRSA infection model, Phage-MPs significantly reduce the bacterial load in major organs, achieving an efficient therapeutic effect. Furthermore, Phage-MPs demonstrate outstanding biocompatibility both in vitro and in vivo. Overall, our research lays the foundation for a new generation of phage-based therapies to combat antibiotic-resistant bacterial infections.

Regenerated silk fibroin coating stable liquid metal nanoparticles enhance photothermal antimicrobial activity of hydrogel for wound infection repair.

The integration of liquid metal (LM) and regenerated silk fibroin (RSF) hydrogel holds great potential for achieving effective antibacterial wound treatment through the LM photothermal effect. However, the challenge of LM's uncontrollable shape-deformability hinders its stable application. To address this, we propose a straightforward and environmentally-friendly ice-bath ultrasonic treatment method to fabricate stable RSF-coated eutectic gallium indium (EGaIn) nanoparticles (RSF@EGaIn NPs). Additionally, a double-crosslinked hydrogel (RSF-P-EGaIn) is prepared by incorporating poly N-isopropyl acrylamide (PNIPAAm) and RSF@EGaIn NPs, leading to improved mechanical properties and temperature sensitivity. Our findings reveal that RSF@EGaIn NPs exhibit excellent stability, and the use of near-infrared (NIR) irradiation enhances the antibacterial behavior of RSF-P-EGaIn hydrogel in vivo. In fact, in vivo testing demonstrates that wounds treated with RSF-P-EGaIn hydrogel under NIR irradiation completely healed within 14 days post-trauma infection, with the formation of new skin and hair. Histological examination further indicates that RSF-P-EGaIn hydrogel promoted epithelialization and well-organized collagen deposition in the dermis. These promising results lay a solid foundation for the future development of drug release systems based on photothermal-responsive hydrogels utilizing RSF-P-EGaIn.

Green, Low-carbon Silk-based Materials in Water Treatment: Current State and Future Trends.

The improper and inadequate treatment of industrial, agricultural, and household wastewater exerts substantial pressure on the existing ecosystem and poses a serious threat to the health of both humans and animals. To address these issues, different types of materials have been employed to eradicate detrimental pollutants from wastewater and facilitate the reuse of water resources. Nevertheless, owing to the challenges associated with the degradation of these traditional materials post-use and their incompatibility with the environment, natural biopolymers have garnered considerable interest. Silk protein, as a biomacromolecule, exhibits advantageous characteristics including environmental friendliness, low carbon emissions, biodegradability, sustainability, and biocompatibility. Considering recent research findings, this comprehensive review outlines the structure and properties of silk proteins and offers a detailed overview of the manufacturing techniques employed in the production of silk-based materials (SBMs) spanning different forms. Furthermore, it conducts an in-depth analysis of the state-of-the-art SBMs for water treatment purposes, encompassing adsorption, catalysis, water disinfection, desalination, and biosensing. The review highlights the potential of SBMs in addressing the challenges of wastewater treatment and provides valuable insights into prospective avenues for further research.

Ultrafast Bi-Directional Bending Moisture-Responsive Soft Actuators through Superfine Silk Rod Modified Bio-Mimicking Hierarchical Layered Structure.

Development of stimulus-responsive materials is crucial for novel soft actuators. Among these actuators, the moisture-responsive actuators are known for their accessibility, eco-friendliness, and robust regenerative attributes. A major challenge of moisture-responsive soft actuators (MRSAs) is achieving significant bending curvature within short response times. Many plants naturally perform large deformation through a layered hierarchical structure in response to moisture stimuli. Drawing inspiration from the bionic structure of Delosperma nakurense (D. nakurense) seed capsule, here the fabrication of an ultrafast bi-directional bending MRSAs is reported. Combining a superfine silk fibroin rod (SFR) modified graphene oxide (GO) moisture-responsive layer with a moisture-inert layer of reduced graphene oxide (RGO), this actuator demonstrated large bi-directional bending deformation (-4.06 ± 0.09 to 10.44 ± 0.00 cm-1) and ultrafast bending rates (7.06 cm-1 s-1). The high deformation rate is achieved by incorporating the SFR into the moisture-responsive layers, facilitating rapid water transmission within the interlayer structure. The complex yet predictable deformations of this actuator are demonstrated that can be utilized in smart switch, robotic arms, and walking device. The proposed SFR modification method is simple and versatile, enhancing the functionality of hierarchical layered actuators. It holds the potential to advance intelligent soft robots for application in confined environments.

Hierarchically patterned protein scaffolds with nano-fibrillar and micro-lamellar structures modulate neural stem cell homing and promote neuronal differentiation.

Biophysical factors are essential in cell survival and behaviors, but constructing a suitable 3D microenvironment for the recruitment of stem cells and exerting their physiological functions remain a daunting challenge. Here, we present a novel silk fibroin (SF)-based fabrication strategy to develop hierarchical microchannel scaffolds for biomimetic nerve microenvironments in vitro. We first modulated the formation of SF nanofibers (SFNFs) that mimic the nanostructures of the native extracellular matrix (ECM) by using graphene oxide (GO) nanosheets as templates. Then, SFNF-GO systems were shaped into 3D porous scaffolds with aligned micro-lamellar structures by freeze-casting. The interconnected microchannels successfully induced cell infiltration and migration to the SFNF-GO scaffolds' interior. Meanwhile, the nano-fibrillar structures and the GO component significantly induced neural stem cells (NSCs) to differentiate into neurons within a short timeframe of 14 d. Importantly, these 3D hierarchical scaffolds induced a mild inflammatory response, extensive cell recruitment, and effective stimulation of NSC neuronal differentiation when implanted in vivo. Therefore, these SFNF-GO lamellar scaffolds with distinctive nano-/micro-topographies hold promise in the fields of nerve injury repair and regenerative medicine.

Metal-Organic Frameworks Nucleated by Silk Fibroin and Modified with Tumor-Targeting Peptides for Targeted Multimodal Cancer Therapy.

Multimodal therapy requires effective drug carriers that can deliver multiple drugs to specific locations in a controlled manner. Here, the study presents a novel nanoplatform constructed using zeolitic imidazolate framework-8 (ZIF-8), a nanoscale metal-organic framework nucleated under the mediation of silk fibroin (SF). The nanoplatform is modified with the newly discovered MCF-7 breast tumor-targeting peptide, AREYGTRFSLIGGYR (AR peptide). Indocyanine green (ICG) and doxorubicin (DOX) are loaded onto the nanoplatform with high drug encapsulation efficiency (>95%). ICG enables the resultant nanoparticles (NPs), called AR-ZS/ID-P, to release reactive oxygen species for photodynamic therapy (PDT) and heat for photothermal therapy (PTT) under near-infrared (NIR) irradiation, promoting NIR fluorescence and thermal imaging to guide DOX-induced chemotherapy. Additionally, the controlled release of both ICG and DOX at acidic tumor conditions due to the dissolution of ZIF-8 provides a drug-targeting mechanism in addition to the AR peptide. When intravenously injected, AR-ZS/ID-P NPs specifically target breast tumors and exhibit higher anticancer efficacy than other groups through ICG-enabled PDT and PTT and DOX-derived chemotherapy, without inducing side effects. The results demonstrate that AR-ZS/ID-P NPs are a promising multimodal theranostic nanoplatform with maximal therapeutic efficacy and minimal side effects for targeted and controllable drug delivery.

Silk Protein-Mediated Biomineralization: From Bioinspired Strategies and Advanced Functions to Biomedical Applications.

Biomineralization refers to the process through which minerals nucleate in a structured manner to form specific crystal structures by the regulating of biomacromolecules. Biomineralization occurs in bones and teeth within the human body, where collagen acts as a template for the nucleation of hydroxyapatite (HA) crystals. Similar to collagen, silk proteins spun by silkworms can also serve as templates for the nucleation and growth of inorganic substances at interfaces. By enabling the binding of silk proteins to inorganic minerals, the process of biomineralization enhances the properties of silk-based materials and broadens their potential applications, rendering them highly promising for use in biomedical applications. In recent years, the development of biomineralized materials using silk proteins has garnered considerable attention in the biomedical field. This comprehensive review outlines the mechanism of biomineral formation mediated by silk proteins, as well as various biomineralization methods used to prepare silk-based biomineralized materials (SBBMs). Additionally, we discuss the physicochemical properties and biological functions of SBBMs, and their potential applications in various fields such as bioimaging, cancer therapy, antibacterial treatments, tissue engineering, and drug delivery. In conclusion, this review highlights the significant role that SBBMs can play in the biomedical field.

Upconversion nanoparticle-based aptasensor for rapid and ultrasensitive detection of Staphylococcus aureus by low-speed centrifugation.

Opportunistic foodborne pathogens such as Staphylococcus aureus (S. aureus) can cause a wide variety of threats to public health. There is an urgent clinical need for a fast, simple, low-cost, and sensitive method. Here, we designed a fluorescence-based aptamer biosensor (aptasensor) for S. aureus detection using core-shell structured upconversion nanoparticles (CS-UCNPs) as a beacon. A S. aureus-specific aptamer was modified on the surface of CS-UCNPs for binding pathogens. The S. aureus bound to CS-UCNPs can then be isolated from the detection system by simple low-speed centrifugation. Thus, an aptasensor was successfully established for the detection of S. aureus. The fluorescence intensity of CS-UCNPs correlated with the concentration of S. aureus within the range of 6.36 × 102 to 6.36 × 108 CFU mL-1, resulting in the detected limit of S. aureus being 60 CFU mL-1. The aptasensor performed well in real food samples (milk) with a detection limit of 146 CFU mL-1 for S. aureus. Furthermore, we applied our aptasensor in chicken muscles for S. aureus detection, and compared it with the plate count gold standard method. There was no significant difference between our aptasensor and the plate count method within the detected limit, while the time for the aptasensor (0.58 h) was shorter than that of the plate count method (3-4 d). Therefore, we succeeded in the design of a simple, sensitive and fast CS-UCNPs aptasensor for S. aureus detection. This aptasensor system would have the potential for the detection of a wide range of bacterial species by switching the corresponding aptamer.

Graphene Oxide-Coated Patterned Silk Fibroin Films Promote Cell Adhesion and Induce Cardiomyogenic Differentiation of Human Mesenchymal Stem Cells.

Cardiac tissue engineering is a promising strategy for the treatment of myocardial damage. Mesenchymal stem cells (MSCs) are extensively used in tissue engineering. However, transformation of MSCs into cardiac myocytes is still a challenge. Furthermore, weak adhesion of MSCs to substrates often results in poor cell viability. Here, we designed a composite matrix based on silk fibroin (SF) and graphene oxide (GO) for improving the cell adhesion and directing the differentiation of MSCs into cardiac myocytes. Specifically, patterned SF films were first produced by soft lithographic. After being treated by air plasma, GO nanosheets could be successfully coated on the patterned SF films to construct the desired matrix (P-GSF). The resultant P-GSF films presented a nano-topographic surface characterized by linear grooves interlaced with GO ridges. The P-GSF films exhibited high protein absorption and suitable mechanical strength. Furthermore, the P-GSF films accelerated the early cell adhesion and directed the growth orientation of MSCs. RT-PCR results and immunofluorescence imaging demonstrated that the P-GSF films significantly improved the cardiomyogenic differentiation of MSCs. This work indicates that patterned SF films coated with GO are promising matrix in the field of myocardial repair tissue engineering.

Association between dietary approaches to stop hypertension eating pattern and lung cancer risk in 98,459 participants: results from a large prospective study.

Background: Dietary approaches to stop hypertension (DASH) eating pattern is linked to anti-inflammatory responses and antioxidation, which overlap with the pathogenesis of lung cancer. However, there is insufficient epidemiological evidence to link this dietary pattern to lung cancer risk conclusively. Aim: To determine if adherence to the DASH diet is linked to a lower risk of developing lung cancer in a large prospective study. Methodology: The data of participants were retrieved from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. A DASH score was calculated based on 8 dietary components to reflect adherence to DASH, with greater scores representing higher adherence. Three Cox proportional hazards models were constructed to analyze the association between DASH scores and lung cancer risk, including an unadjusted model and two adjusted models (model 1 for demographics and model 2 for fully confounding factors). A restricted cubic spline plot was utilized to illustrate the likelihood of developing lung cancer across the entire range of DASH scores. The association between each of the 8 DASH components and the risk of lung cancer was assessed separately. Several subgroup analyses were conducted to identify potential modifiers, and several sensitivity analyses were performed to verify the robustness of the findings. Results: The study involved 98,459 individuals in total. The mean (standard deviation) DASH score was 24.00 (4.62) points, along with the mean follow-up period of 8.84 (1.94) years. Lung cancer was identified in 1642 cases over 869807.9 person-years of follow-up, and the overall incidence rate was 0.189 cases/100 person-years. Participants in the highest quartile in the fully adjusted model had a relatively decreased risk of developing lung cancer in comparison to those in the lowest quartile (HRquartile 4 versus 1: 0.647; 95% CI: 0.557, 0.752; Ptrend < 0.001). The restricted cubic spline plot demonstrated that DASH score and lung cancer risk were inversely associated and had a linear dose-response relationship (Pnon-linear = 0.944). According to subgroup analyses, those who were current or former smokers had a stronger inverse connection than those who never smoked (Pinteraction = 0.013). The results remained robust after several sensitivity analyses. Conclusion: The risk of lung cancer was inversely associated with DASH scores in the US population. This suggests that following the DASH pattern can help prevent lung cancer, especially for current or former smokers. More epidemiological evidence from other regions and populations is needed to confirm our findings.

Novel Biomaterial-Binding/Osteogenic Bi-Functional Peptide Binds to Silk Fibroin Membranes to Effectively Induce Osteogenesis In Vitro and In Vivo.

Peptides can introduce new functions to biomaterials but their immobilization usually relies on inefficient physical adsorption or tedious chemical conjugation. Using the Bombyx mori silk fibroin (SF) membrane (SFm) as a model biomaterial, here, we demonstrate a universal strategy for discovering new peptides that can "stick" to a biomaterial to functionalize it. Specifically, two peptide motifs, one screened by phage display biopanning for binding to the biomaterial (i.e., SF) and another derived from an osteogenic growth factor (i.e., bone morphogenetic protein-2), are fused into a new chimeric peptide that can bind to SFm for more efficient osteogenesis. Theoretical simulations and experimental assays confirm that the chimeric peptide binds to SF with high affinity, facilely achieving its immobilization onto SFm. The peptide enables SFm to effectively induce osteogenic differentiation of human mesenchymal stem cells (MSCs) even without other osteogenic inducers and efficiently stimulate bone regeneration in a subcutaneous rat model in 8 weeks, even without MSC seeding, while not causing inflammatory responses. Since biomaterial-binding peptides can be readily screened using phage display and functional peptides can be generated from growth factors, our work suggests a universal strategy for combining them to seek new peptides for binding and functionalizing biomaterials.

Integration of genetically engineered virus nanofibers and fibrin to form injectable fibrous neuron-rich hydrogels and enable neural differentiation.

Peripheral nerve injury (PNI) results in persistent pain, a burning sensation, tingling, or complete loss of sensation. Treating large nerve defects is a major challenge, and the use of autologous nerve grafts (ANGs) cannot overcome this challenge. Hence, substitutes for ANGs that can serve as artificial nerve fibers are urgently needed in the clinical treatment of PNI. To develop such substitutes, we genetically engineered a virus nanofiber (M13 phage) that displays a high density of RGD peptide on its sidewall, producing an RGD-displaying phage (R-phage). In the presence of neural stem cells (NSCs), the resultant negatively charged R-phage nanofibers were electrostatically bound to a complex (with a net positive charge) of negatively charged fibrin and positively charged polyethyleneimine (PEI). The biocompatible injectable fibrin gel (FG) was integrated with R-phage and seeded with NSCs, forming a hydrogel termed R-phage/FG, which is further extruded through a syringe to form a fiber. The developed fiber-shaped hydrogel exhibited the desired excellent physical-chemical properties, and controllable and appropriate mechanical properties (170-240 kPa) similar to native nerve. The R-phage/FG not only promoted NSC adhesion, infiltration, and proliferation, but also induced efficient preferential differentiation of NSCs into neurons in the hydrogels in a non-differentiating medium within only 4 days. After the NSC-seeded R-phage/FG was injected into the long-gap (10 mm) defect of a rat's sciatic nerve, a solid neuron-rich hydrogel fiber was formed as an artificial nerve fiber graft that stimulated neurogenesis in the transplanted area within 60 days for nerve regeneration. These results suggest that the R-phage/FG fiber represents a potential substitute ANG for repairing large nerve injuries. This work demonstrates a new phage-based biomaterial that can be used as a graft for treating PNI through neurogenesis.

Work situation of patients with stroke who have returned to work: a scoping review protocol.

INTRODUCTION: The incidence of stroke in working-age adults is increasing. Many patients face cognitive, emotional and physical impairments and their subsequent influences on returning to work. An increasing number of studies have been conducted on the transformation from unemployment to returning to work. The criteria for returning to work only used the 'working yes/no' as the primary outcome. Although some researchers have investigated the characteristics of patients with stroke who have returned to work, there is a paucity of evidence regarding the work situation. This scoping review aimed to examine and map the work situation of patients with stroke who have returned to work. METHODS AND ANALYSIS: This study will be based on the Joanna Briggs Institute Reviewers' Manual for scoping reviews. A systematic literature search will be conducted using related medical subject headings and keywords on the work situation of patients with stroke who have returned to work. Relevant publications will be searched using 17 data sources, including grey literature sources, published in English or Chinese between 1957 and 2022. None of the articles will have restrictions on the data sources or study designs. The study selection and search results will be reported and presented according to the Preferred Reporting Items for Systematic Review and Meta-Analyses extension for scoping reviews flow diagram. The results will be presented in a table format based on the data extraction tool. ETHICS AND DISSEMINATION: This study is exempted from a medical ethical review. This scoping review addresses the knowledge gap by identifying and synthesising the work situation of patients with stroke who have returned to work, which will provide helpful information for various stakeholders. This scoping review will be submitted and published in a peer-reviewed scientific journal.

Efficient Tumor Immunotherapy through a Single Injection of Injectable Antigen/Adjuvant-Loaded Macroporous Silk Fibroin Microspheres.

Synthetic or natural materials have been used as vaccines in cancer immunotherapy. However, using them as vaccines necessitates multiple injections or surgical implantations. To tackle such daunting challenges, we develop an injectable macroporous Bombyx mori (B. mori) silk fibroin (SF) microsphere loaded with antigens and immune adjuvants to suppress established tumors with only a single injection. SF microspheres can serve as a scaffold by injection and avoid surgical injury as seen in traditional scaffold vaccines. The macroporous structure of the vaccine facilitates the recruitment of immune cells and promotes the activation of dendritic cells (DCs), resulting in a favorable immune microenvironment that further induces strong humoral and cellular immunity. We have also modified the vaccine into a booster version by simply allowing the antigens to be adsorbed onto the SF microspheres. The booster vaccine highly efficiently suppresses tumor growth by improving the cytotoxic T lymphocyte (CTL) response. In general, these results demonstrate that the macroporous SF microspheres can serve as a facile platform for tumor vaccine therapy in the future. Since the SF microspheres are also potential scaffolds for tissue regeneration, their use as a vaccine platform will enable their applications in eradicating tumors while regenerating healthy tissue to heal the tumor-site cavity.

Target-Triggered Formation of Artificial Enzymes on Filamentous Phage for Ultrasensitive Direct Detection of Circulating miRNA Biomarkers in Clinical Samples.

Integrating artificial enzymes onto nanostructures target- and site-specifically is still a challenge. Here we show that target miRNAs trigger the formation of DNAzyme site-specifically at the tip of filamentous phage for detecting miRNA biomarkers. Through an antibody-modified oligonucleotide, the tip of the phage with magnetic nanoparticles on the sidewall captures a target miRNA, inducing the formation of DNAzyme that extends from the phage tip through a hybridization chain reaction. After magnetic separation, the resultant complex catalyzes a colorimetric reaction with the signal correlated to target concentrations, leading to the quantification of miRNAs with a detection limit of 5.0 fM, about 103 folds lower than the phage-free approach. Our approach can differentiate miRNA mutants and quantify miRNA in human plasma, tumor cells, and tissues with high sensitivity, suggesting that the target-triggered integration of enzymes and phages holds promise for searching for new catalysts.

Detection, prevention and treatment of COVID-19 and opportunities for nanobiotechnology.

Since the outbreak of COVID-19, the number of confirmed cases and deaths has increased globally at a dramatic speed. In view of the serious health threat to humans, this review discusses the state-of-the-art studies about fighting this disease. It summarizes the current strategies and recent advances in detecting, preventing, and treating COVID-19 and interprets the underlying mechanisms in detail. Detection of COVID-19 can be successfully achieved by multiple techniques such as polymerase chain reaction, computed tomography imaging, and nano-biosensing. Inactivated virus vaccine, nucleic acid vaccine, and different nanoparticles have been employed to effectively prevent COVID-19. A variety of agents such as antiviral agents, neutralizing antibodies, and nanotherapeutics have been developed to treat COVID-19 with exciting efficacy. Although nanobiotechnology has shown great potential in the diagnosis, prevention, and treatment of COVID-19, efforts should be made to explore new biocompatible nano-biomaterials to advance this field to clinical applications. Hence, nanobiotechnology paves a new way to detect, prevent, and treat COVID-19 effectively.