Tissue engineering: Still facing a long way ahead

Harnessing DNA origami's therapeutic potential for revolutionizing cardiovascular disease treatment: A comprehensive review

DNA origami is a cutting-edge nanotechnology approach that creates precise and detailed 2D and 3D nanostructures. The crucial feature of DNA origami is how it is created, which enables precise control over its size and shape. Biocompatibility, targetability, programmability, and stability are further advantages that make it a potentially beneficial technique for a variety of applications. The preclinical studies of sophisticated programmable nanomedicines and nanodevices that can precisely respond to particular disease-associated triggers and microenvironments have been made possible by recent developments in DNA origami. These stimuli, which are endogenous to the targeted disorders, include protein upregulation, pH, redox status, and small chemicals. Oncology has traditionally been the focus of the majority of past and current research on this subject. Therefore, in this comprehensive review, we delve into the intricate world of DNA origami, exploring its defining features and capabilities. This review covers the fundamental characteristics of DNA origami, targeting DNA origami to cells, cellular uptake, and subcellular localization. Throughout the review, we emphasised on elucidating the imperative for such a therapeutic platform, especially in addressing the complexities of cardiovascular disease (CVD). Moreover, we explore the vast potential inherent in DNA origami technology, envisioning its promising role in the realm of CVD treatment and beyond.

Tetramethylpyrazine-loaded electroconductive hydrogels promote tissue repair after spinal cord injury by protecting the blood-spinal cord barrier and neurons

Spinal cord injury (SCI) usually induces profound microvascular dysfunction. It disrupts the integrity of the blood-spinal cord barrier (BSCB), which could trigger a cascade of secondary pathological events that manifest as neuronal apoptosis and axonal demyelination. These events can further lead to irreversible neurological impairments. Thus, reducing the permeability of the BSCB and maintaining its substructural integrity are essential to promote neuronal survival following SCI. Tetramethylpyrazine (TMP) has emerged as a potential protective agent for treating the BSCB after SCI. However, its therapeutic potential is hindered by challenges in the administration route and suboptimal bioavailability, leading to attenuated clinical outcomes. To address this challenge, traditional Chinese medicine, TMP, was used in this study to construct a drug-loaded electroconductive hydrogel for synergistic treatment of SCI. A conductive hydrogel combined with TMP demonstrates good electrical and mechanical properties as well as superior biocompatibility. Furthermore, it also facilitates sustained local release of TMP at the implantation site. Furthermore, the TMP-loaded electroconductive hydrogel could suppress oxidative stress responses, thereby diminishing endothelial cell apoptosis and the breakdown of tight junction proteins. This concerted action repairs BSCB integrity. Concurrently, myelin-associated axons and neurons are protected against death, which meaningfully restore neurological functions post spinal cord injury. Hence, these findings indicate that combining the electroconductive hydrogel with TMP presents a promising avenue for potentiating drug efficacy and synergistic repair following SCI.

Application of tissue engineering techniques in tracheal repair: a bibliometric study

Transplantation of tissue-engineered trachea is an effective treatment for long-segment tracheal injury. This technology avoids problems associated with a lack of donor resources and immune rejection, generating an artificial trachea with good biocompatibility. To our knowledge, a systematic summary of basic and clinical research on tissue-engineered trachea in the last 20 years has not been conducted. Here, we analyzed the development trends of tissue-engineered trachea research by bibliometric means and outlined the future perspectives in this field. The Web of Science portal was selected as the data source. CiteSpace, VOSviewer, and the Bibliometric Online Analysis Platform were used to analyze the number of publications, journals, countries, institutions, authors, and keywords from 475 screened studies. Between 2000 and 2023, the number of published studies on tissue-engineered trachea has been increasing. Biomaterials published the largest number of papers. The United States and China have made the largest contributions to this field. University College London published the highest number of studies, and the most productive researcher was an Italian scholar, Paolo Macchiarini. However, close collaborations between various researchers and institutions from different countries were generally lacking. Despite this, keyword analysis showed that manufacturing methods for tracheal stents, hydrogel materials, and 3D bioprinting technology are current popular research topics. Our bibliometric study will help scientists in this field gain an in-depth understanding of the current research progress and development trends to guide their future work, and researchers in related fields will benefit from the introduction to transplantation methods of tissue-engineered trachea.

Nanoenzyme-Reinforced Multifunctional Scaffold Based on Ti3C2Tx MXene Nanosheets for Promoting Structure-Functional Skeletal Muscle Regeneration via Electroactivity and Microenvironment Management

The completed volumetric muscle loss (VML) regeneration remains a challenge due to the limited myogenic differentiation as well as the oxidative, inflammatory, and hypoxic microenvironment. Herein, a 2D Ti3C2Tx MXene@MnO2 nanocomposite with conductivity and microenvironment remodeling was fabricated and applied in developing a multifunctional hydrogel (FME) scaffold to simultaneously conquer these hurdles. Among them, Ti3C2Tx MXene with electroconductive ability remarkably promotes myogenic differentiation via enhancing the myotube formation and upregulating the relative expression of the myosin heavy chain (MHC) protein and myogenic genes (MyoD and MyoG) in myogenesis. The MnO2 nanoenzyme-reinforced Ti3C2Tx MXene significantly reshapes the hostile microenvironment by eliminating reactive oxygen species (ROS), regulating macrophage polarization from M1 to M2 and continuously supplying O2. Together, the FME hydrogel as a bioactive multifunctional scaffold significantly accelerates structure-functional VML regeneration in vivo and represents a multipronged strategy for the VML regeneration via electroactivity and microenvironment management.

Porous composite hydrogels with improved MSC survival for robust epithelial sealing around implants and M2 macrophage polarization

The application of mesenchymal stem cell (MSC)-based therapy is expected to make a significant contribution to the improvement of epithelial sealing around implants. However, there is currently no optimal MSC delivery biomaterial for clinical application in peri-implant epithelium (PIE) integration. In this study, we show that injectable photo-cross-linkable porous gelatin methacryloyl (GelMA)/silk fibroin glycidyl methacrylate (SilMA) hydrogels encapsulating gingival tissue-derived MSCs (GMSCs) are a simple and practical approach for re-epithelization applications. The hydrogels played a prominent role in supporting the proliferation, survival, and spread of GMSCs. Moreover, it was found that GMSCs-laden Porous GelMA/SilMA hydrogels could significantly upregulate the hemidesmosomes (HDs)-related genes and proteins expression and promote M2 polarization while inhibiting M1 polarization in vitro. Based on a rat model of early implant placement, application of the MSC-loaded hydrogels could enhance the protein expression of LAMA3 and BP180 (COL17A1) at the implant-PIE interface and reduce horseradish peroxidase (HRP) penetration between the implants and PIE. Noticeably, hydrogel-based MSC therapy contributed to augmenting M2 macrophage infiltration at two time points in the gingival connective tissue around implants. These findings demonstrated that GMSCs-laden Porous GelMA/SilMA hydrogels could facilitate epithelial sealing around implants and M2-polarized macrophages and may be a novel and facile therapeutic strategy for implant-PIE integration. STATEMENT OF SIGNIFICANCE: In the case of poor integration between the implant and gingival epithelium, peri-implantitis can develop, which is one of the main causes of implant failure. While stem cell therapy has tremendous potential for addressing this issue, poor cell survival and engraftment compromise the effectiveness of the therapy. Due to the excellent modifiable and tunable properties of gelatin and silk fibroin, injectable photo-cross-linkable porous hydrogels were developed using gelatin methacryloyl (GelMA) and silk fibroin glycidyl methacrylate (SilMA) as delivery vehicles for gingiva-derived MSCs (GMSCs). Porous GelMA/SilMA not only enhanced the proliferation and viability of GMSCs but also promoted their immunomodulatory capability for favorable epithelial sealing around implants. Overall, GMSCs-seeded porous hydrogels could be promising strategies for re-epithelization treatment.

Silk fibroin-based biomaterials for disc tissue engineering

Low back pain is the major cause of disability worldwide, and intervertebral disc degeneration (IVDD) is one of the most important causes of low back pain. Currently, there is no method to treat IVDD that can reverse or regenerate intervertebral disc (IVD) tissue, but the recent development of disc tissue engineering (DTE) offers a new means of addressing these disadvantages. Among numerous biomaterials for tissue engineering, silk fibroin (SF) is widely used due to its easy availability and excellent physical/chemical properties. SF is usually used in combination with other materials to construct biological scaffolds or bioactive substance delivery systems, or it can be used alone. The present article first briefly outlines the anatomical and physiological features of IVD, the associated etiology and current treatment modalities of IVDD, and the current status of DTE. Then, it highlights the characteristics of SF biomaterials and their latest research advances in DTE and discusses the prospects and challenges in the application of SF in DTE, with a view to facilitating the clinical process of developing interventions related to IVD-derived low back pain caused by IVDD.

Technical and engineering considerations for designing therapeutics and delivery systems

The newly-emerged pathological conditions and increased rates of drug resistance necessitate application of the state-of-the-art technologies for accelerated discovery of the therapeutic candidates and obtaining comprehensive knowledge about their targets, action mechanisms, and interactions within the body including those between the receptors and drugs. Using the physics- and chemistry-based modern techniques for theranostic purposes, preparing smart carriers, local delivery of genes or drugs, and enhancing pharmaceutical bioavailability could be of great value against the hard-to-treat diseases and growing drug resistance. Besides the artificial intelligence- and quantum-based techniques, crystal engineering capable of designing new molecules with appropriate characteristics, improving the stability and bioavailability of poorly soluble drugs, and efficient carrier development could play a crucial role in manufacturing efficient pharmaceuticals and reducing the adverse events. In this context, identifying the structures and behaviors of crystals and predicting their characteristics are of great value. Electron diffraction by accelerated analysis of the chemicals and sensitivity to charge alterations, electromechanical tools for controlled delivery of therapeutics, mechatronics via fabrication of multi-functional smart products including the organ-on-chip devices for healthcare applications, and optomechatronics by overcoming the limitations of conventional biomedical techniques could address the unmet biomedical requirements and facilitate development of more effective theranostics with improved outcomes.

Recent advances in PLLA-based biomaterial scaffolds for neural tissue engineering: Fabrication, modification, and applications

Repairing and regenerating injured neural tissue remains a worldwide challenge. Tissue engineering (TE) has been highlighted as a potential solution to provide functional substitutes for damaged organs or tissue. Among the biocompatible and biodegradable materials, poly-L-lactic-acid (PLLA) has been widely investigated in the TE field because of its tunable mechanical properties and tailorable surface functionalization. PLLA-based biomaterials can be engineered as scaffolds that mimic neural tissue extracellular matrix and modulate inflammatory responses. With technological advances, PLLA-based scaffolds can also have well-controlled three-dimensional sizes and structures to facilitate neurite extension. Furthermore, PLLA-based scaffolds have the potential to be used as drug-delivery carriers with controlled release. Moreover, owing to the good piezoelectric properties and capacity to carry conductive polymers, PLLA-based scaffolds can be combined with electrical stimulation to maintain stemness and promote axonal guidance. This mini-review summarizes and discusses the fabrication and modification techniques utilized in the PLLA-based biomaterial scaffolds for neural TE. Recent applications in peripheral nerve and spinal cord regeneration are also presented, and it is hoped that this will guide the future development of more effective and multifunctional PLLA-based nerve scaffolds.

The Proangiogenic Potential of Rat Adipose-Derived Stromal Cells with and without Cell-Sheet Induction: A Comparative Study

A functional vasculature for survival remains a challenge for tissue regeneration, which is indispensable for oxygen and nutrient supply. Utilizing mesenchymal stromal cells (MSCs) to alleviate tissue ischemia and repair dysfunctional or damaged endothelium is a promising strategy. Compared to other populations of MSCs, adipose-derived stromal cells (ASCs) possess a more significant proangiogenic potential and are abundantly available. Cell sheet technology has recently been widely utilized in bone engineering. Compared to conventional methods of seeding seed cell suspension onto biological scaffolds, cell sheet technology prevents cell loss and preserves the extracellular matrix (ECM). Nevertheless, the proangiogenic potential of ASC sheets remains unknown. In this study, rat ASC sheets were constructed, and their macro- and microstructures were examined. In addition, we investigated the effects of ASCs and ASC sheets on the biological properties and angiogenic capacity of endothelial cells (ECs). The results demonstrated that the ASC sheets gradually thickened as the number of cells and ECM increased over time and that the cells were in an active state of secretion. Similar to ASC-CM, the conditioned medium (CM) of ASC sheets could significantly enhance the proliferative capacity of ECs. ASC sheet-CM has significant advantages over ASC-CM in promoting the migration and angiogenesis of ECs, where the exosomes secreted by ASC sheets play an essential role. Therefore, using ASC sheets for therapeutic tissue and organ regeneration angiogenesis may be a valuable strategy.

Discussing the final size and shape of the reconstructed tissues in tissue engineering

Tissue engineering (TE) has made a revolution in repairing, replacing, or regenerating tissues or organs, but it has still a long way ahead. The mechanical properties along with suitable physicochemical and biological characteristics are the initial criteria for scaffolds in TE that should be fulfilled. This research will provide another point of view toward TE challenges concerning the morphological and geometrical aspects of the reconstructed tissue and which parameters may affect it. Based on our survey, there is a high possibility that the final reconstructed tissue may be different in size and shape compared to the original design scaffold. Thereby, the 3D-printed scaffold might not guarantee an accurate tissue reconstruction. The main justification for this is the unpredicted behavior of cells, specifically in the outer layer of the scaffold. It can also be a concern when the scaffold is implanted while cell migration cannot be controlled through the in vivo signaling pathways, which might cause cancer challenges. To sum up, it is concluded that more studies are necessary to focus on the size and geometry of the final reconstructed tissue.

Nanobionics: From plant empowering to the infectious disease treatment

Infectious diseases (ID) are serious threats against the global health and socio-economic conditions. Vaccination usually plays a key role in disease prevention, however, insufficient efficiency or immunogenicity may be quite challenging. Using the advanced vectors for delivery of vaccines with suitable efficiency, safety, and immune-modulatory activity, and tunable characteristics could be helpful, but there are no systematic reviews confirming the capabilities of the vaccine delivery systems for covering various types of pathogens. Furthermore, high rates of the infections, transmission, and fatal ratio and diversity of the pathogens and infection mechanisms may negatively influence vaccine effectiveness. The absence of highly-effective antibiotics against the resistant strains of bacteria and longevity of antibiotic testing have provoked increasing needs towards the application of more accurate and specific theranostic strategies including the nanotechnology-based ones. Nanobionics which is based on the charge storage and transport in the molecular structures, could be of key value in the molecular diagnostic tests and highly-specific electro-analytical methods or devices. Such devices based on the early disease diagnostics might be of critical significance against various types of diseases. This article highlights the significance of nanobionics against ID.

Adipose tissue derived stromal cells in a gelatin based 3D matrix with exclusive ascorbic acid signalling emerged as a novel neural tissue engineering construct – An innovative prototype for soft tissue

The current study investigated a triad, which comprises of adipose tissue derived stem cells isolated from infrapatellar fat pad and gelatin/polyvinyl alcohol (PVA)-based matrix with exclusive ascorbic acid signalling. Though, the bio-mechanical properties of the gelatin–PVA blended scaffolds in wet condition are equivalent to the ECM of soft tissues in general, in this study, the triad was tested as a model for neural tissue engineering. Apart from being cytocompatible and biocompatible, the porosity of the scaffold has been designed in such a manner that it facilitates the cell signalling and enables the exchange of nutrients and gases. The highly proliferative stem cells from Passage 2 were characterized using both, mesenchymal and embryonic stem cell markers. As an initial exploration the mesenchymal stem cells at Passage 4 were exposed to ascorbic acid and basic fibroblast growth factor signalling for neuronal differentiation in 2D environment independently. The MSCs successfully differentiated and acquired neuron specific markers related to cytoskeleton and synapses. Subsequently, three phases of experiments have been conducted on the 3D gelatin/PVA matrix to prove their efficacy, the growth of stem cells, growth of differentiated neurons and the in situ growth and differentiation of MSCs. The scaffold was conducive and directed MSCs to neuronal lineage under specific signalling. Overall, this organotypic model triad could open a new avenue in the field of soft tissue engineering as a simple and effective tissue construct.

The Biocompatibility of Multi-Source Stem Cells and Gelatin-Carboxymethyl Chitosan-Sodium Alginate Hybrid Biomaterials

BACKGROUND

Nowadays, biological tissue engineering is a growing field of research. Biocompatibility is a key indicator for measuring tissue engineering biomaterials, which is of great significance for the replacement and repair of damaged tissues.

METHODS

In this study, using gelatin, carboxymethyl chitosan, and sodium alginate, a tissue engineering material scaffold that can carry cells was successfully prepared. The material was characterized by Fourier transforms infrared spectroscopy. In addition, the prepared scaffolds have physicochemical properties, such as swelling ratio, biodegradability. we observed the biocompatibility of the hydrogel to different adult stem cells (BMSCs and ADSCs) in vivo and in vitro. Adult stem cells were planted on gelatin-carboxymethyl chitosan-sodium alginate (Gel/SA/CMCS) hydrogels for 7 days in vitro, and the survival of stem cells in vitro was observed by live/died staining. Gel/SA/CMCS hydrogels loaded with stem cells were subcutaneously transplanted into nude mice for 14 days of in vivo culture observation. The survival of adult stem cells was observed by staining for stem cell surface markers (CD29, CD90) and Ki67.

RESULTS

The scaffolds had a microporous structure with an appropriate pore size (about 80 μm). Live/died staining showed that adult stem cells could stably survive in Gel/SA/CMCS hydrogels for at least 7 days. After 14 days of culture in nude mice, Ki67 staining showed that the stem cells supported by Gel/SA/CMCS hydrogel still had high proliferation activity.

CONCLUSION

Gel/SA/CMCSs hydrogel has a stable interpenetrating porous structure, suitable swelling performance and degradation rate, can promote and support the survival of adult stem cells in vivo and in vitro, and has good biocompatibility. Therefore, Gel/SA/CMCS hydrogel is a strong candidate for biological tissue engineering materials.

Recent advances of chitosan-based nanoparticles for biomedical and biotechnological applications

Chitosan is a natural alkaline polysaccharide, which widely exists in marine crustaceans such as shrimp and crab, has been shown to have various biological activities. It has attracted considerable attention in biomedicine and nanomaterials fields because of its excellent properties, such as biocompatibility, biodegradability, non-toxicity and easy access. In addition, because of active hydroxyl and amino groups in chitosan molecules, different functional groups can be introduced into chitosan molecules by molecular modification or chemical modification, which extends their applications. Nanoparticles with small size and large surface area can be used as diagnostic and therapeutic tools in the biomedical field, which make it easier to understand, detect and treat human diseases. The nanomaterials based on chitosan have important applications in biomedicine, industry, pharmacy, agriculture, and other fields. This review highlights the recent advances on chitosan-based nanoparticles for antibacterial property, drug and gene delivery, cancer and hyperthermia therapy, cell imaging, restorative dentistry, wound healing, tissue engineering and other biomedical fields. The nanotechnology fields involving biosensors, water treatment, food industry and agriculture are also briefly reviewed.

The biological applications of DNA nanomaterials: current challenges and future directions

DNA, a genetic material, has been employed in different scientific directions for various biological applications as driven by DNA nanotechnology in the past decades, including tissue regeneration, disease prevention, inflammation inhibition, bioimaging, biosensing, diagnosis, antitumor drug delivery, and therapeutics. With the rapid progress in DNA nanotechnology, multitudinous DNA nanomaterials have been designed with different shape and size based on the classic Watson-Crick base-pairing for molecular self-assembly. Some DNA materials could functionally change cell biological behaviors, such as cell migration, cell proliferation, cell differentiation, autophagy, and anti-inflammatory effects. Some single-stranded DNAs (ssDNAs) or RNAs with secondary structures via self-pairing, named aptamer, possess the ability of targeting, which are selected by systematic evolution of ligands by exponential enrichment (SELEX) and applied for tumor targeted diagnosis and treatment. Some DNA nanomaterials with three-dimensional (3D) nanostructures and stable structures are investigated as drug carrier systems to delivery multiple antitumor medicine or gene therapeutic agents. While the functional DNA nanostructures have promoted the development of the DNA nanotechnology with innovative designs and preparation strategies, and also proved with great potential in the biological and medical use, there is still a long way to go for the eventual application of DNA materials in real life. Here in this review, we conducted a comprehensive survey of the structural development history of various DNA nanomaterials, introduced the principles of different DNA nanomaterials, summarized their biological applications in different fields, and discussed the current challenges and further directions that could help to achieve their applications in the future.

Is the Conjunctiva a Potential Target for Advanced Therapy Medicinal Products?

The conjunctiva is a complex ocular tissue that provides mechanical, sensory, and immune protection for the ocular surface. It is affected by many diseases through different pathological mechanisms. If a disease is not treated and conjunctival function is not fully restored, the whole ocular surface and, therefore, sight is at risk. Different therapeutic approaches have been proposed, but there are still unsolved conjunctival alterations that require more sophisticated therapeutic options. Advanced therapy medicinal products (ATMPs) comprise a wide range of products that includes cell therapy, tissue engineering, and gene therapy. To the best of our knowledge, there is no commercialized ATMP specifically for conjunctival treatment yet. However, the conjunctiva can be a potential target for ATMPs for different reasons. In this review, we provide an overview of the advances in experimental phases of potential ATMPs that primarily target the conjunctiva. Important advances have been achieved through the techniques of cell therapy and tissue engineering, whereas the use of gene therapy in the conjunctiva is still marginal. Undoubtedly, future research in this field will lead to achieving commercially available ATMPs for the conjunctiva, which may provide better treatments for patients.

Tendon tissue engineering: Cells, growth factors, scaffolds and production techniques

Tendon injuries are a global health problem that affects millions of people annually. The properties of tendons make their natural rehabilitation a very complex and long-lasting process. Thanks to the development of the fields of biomaterials, bioengineering and cell biology, a new discipline has emerged, tissue engineering. Within this discipline, diverse approaches have been proposed. The obtained results turn out to be promising, as increasingly more complex and natural tendon-like structures are obtained. In this review, the nature of the tendon and the conventional treatments that have been applied so far are underlined. Then, a comparison between the different tendon tissue engineering approaches that have been proposed to date is made, focusing on each of the elements necessary to obtain the structures that allow adequate regeneration of the tendon: growth factors, cells, scaffolds and techniques for scaffold development. The analysis of all these aspects allows understanding, in a global way, the effect that each element used in the regeneration of the tendon has and, thus, clarify the possible future approaches by making new combinations of materials, designs, cells and bioactive molecules to achieve a personalized regeneration of a functional tendon.

The biomedical significance of multifunctional nanobiomaterials: The key components for site-specific delivery of therapeutics

The emergence of nanotechnology has provided the possibilities to overcome the potential problems associated with the development of pharmaceuticals including the low solubility, non-specific cellular uptake or action, and rapid clearance. Regarding the biomaterials (BMs), huge efforts have been made for improving their multi-functionalities via incorporation of various nanomaterials (NMs). Nanocomposite hydrogels with suitable properties could exhibit a variety of beneficial effects in biomedicine particularly in the delivery of therapeutics or tissue engineering. NMs including the silica- or carbon-based ones are capable of integration into various BMs that might be due to their special compositions or properties such as the hydrophilicity, hydrophobicity, magnetic or electrical characteristics, and responsiveness to various stimuli. This might provide multi-functional nanobiomaterials against a wide variety of disorders. Meanwhile, inappropriate distribution or penetration into the cells or tissues, bio-nano interface complexity, targeting ability loss, or any other unpredicted phenomena are the serious challenging issues. Computational simulations and models enable development of NMs with optimal characteristics and provide a deeper knowledge of NM interaction with biosystems. This review highlights the biomedical significance of the multifunctional NMs particularly those applied for the development of 2-D or 3-D BMs for a variety of applications including the site-specific delivery of therapeutics. The powerful impacts of the computational techniques on the design process of NMs, quantitation and prediction of protein corona formation, risk assessment, and individualized therapy for improved therapeutic outcomes have also been discussed.

The significance of bioengineered nanoplatforms against SARS-CoV-2: From detection to genome editing

COVID-19 outbreak can impose serious negative impacts on the infrastructures of societies including the healthcare systems. Despite the increasing research efforts, false positive or negative results that may be associated with serologic or even RT-PCR tests, inappropriate or variable immune response, and high rates of mutations in coronavirus may negatively affect virus detection process and effectiveness of the vaccines or drugs in development. Nanotechnology-based research attempts via developing state-of-the-art techniques such as nanomechatronics ones and advanced materials including the sensors for detecting the pathogen loads at very low concentrations or site-specific delivery of therapeutics, and real-time protections against the pandemic outbreaks by nanorobots can provide outstanding biomedical breakthroughs. Considering the unique characteristics of pathogens particularly the newly-emerged ones and avoiding the exaggerated optimism or simplistic views on the prophylactic and therapeutic approaches including the one-size-fits-all ones or presenting multiple medications that may be associated with synergistic toxicities rather than enhanced efficiencies might pave the way towards the development of more appropriate treatment strategies with reduced safety concerns. This paper highlights the significance of nanoplatforms against the viral disorders and their capabilities of genome editing that may facilitate taking more appropriate measures against SARS-CoV-2.

The capabilities of nanoelectronic 2-D materials for bio-inspired computing and drug delivery indicate their significance in modern drug design

Remarkable advancements in the computational techniques and nanoelectronics have attracted considerable interests for development of highly-sophisticated materials (Ms) including the theranostics with optimal characteristics and innovative delivery systems. Analyzing the huge amounts of multivariate data and solving the newly-emerged complicated problems including the healthcare-related ones have created increasing demands for improving the computational speed and minimizing the consumption of energy. Shifting towards the non-von Neumann approaches enables performing specific computational tasks and optimizing the processing of signals. Besides usefulness for neuromorphic computing and increasing the efficiency of computation energy, 2-D electronic Ms are capable of optical sensing with ultra-fast and ultra-sensitive responses, mimicking the neurons, detection of pathogens or biomolecules, and prediction of the progression of diseases, assessment of the pharmacokinetics/pharmacodynamics of therapeutic candidates, mimicking the dynamics of the release of neurotransmitters or fluxes of ions that might provide a deeper knowledge about the computations and information flow in the brain, and development of more effective treatment protocols with improved outcomes. 2-D Ms appear as the major components of the next-generation electronically-enabled devices for highly-advanced computations, bio-imaging, diagnostics, tissue engineering, and designing smart systems for site-specific delivery of therapeutics that might result in the reduced adverse effects of drugs and improved patient compliance. This manuscript highlights the significance of 2-D Ms in the neuromorphic computing, optimizing the energy efficiency of the multi-step computations, providing novel architectures or multi-functional systems, improved performance of a variety of devices and bio-inspired functionalities, and delivery of theranostics.

Nanotheranostics against COVID-19: From multivalent to immune-targeted materials

Destructive impacts of COVID-19 pandemic worldwide necessitates taking more appropriate measures for mitigating virus spread and development of the effective theranostic agents. In general, high heterogeneity of viruses is a major challenging issue towards the development of effective antiviral agents. Regarding the coronavirus, its high mutation rates can negatively affect virus detection process or the efficiency of drugs and vaccines in development or induce drug resistance. Bioengineered nanomaterials with suitable physicochemical characteristics for site-specific therapeutic delivery, highly-sensitive nanobiosensors for detection of very low virus concentration, and real-time protections using the nanorobots can provide roadmaps towards the imminent breakthroughs in theranostics of a variety of diseases including the COVID-19. Besides revolutionizing the classical disinfection procedures, state-of-the-art nanotechnology-based approaches enable providing the analytical tools for accelerated monitoring of coronavirus and associated biomarkers or drug delivery towards the pulmonary system or other affected organs. Multivalent nanomaterials capable of interaction with multivalent pathogens including the viruses could be suitable candidates for viral detection and prevention of further infections. Besides the inactivation or destruction of the virus, functionalized nanoparticles capable of modulating patient's immune response might be of great significance for attenuating the exaggerated inflammatory reactions or development of the effective nanovaccines and medications against the virus pandemics including the COVID-19.

Silk-Based Biomaterials for Cardiac Tissue Engineering

Cardiovascular diseases are one of the leading causes of death globally. Among various cardiovascular diseases, myocardial infarction is an important one. Compared with conventional treatments, cardiac tissue engineering provides an alternative to repair and regenerate the injured tissue. Among various types of materials used for tissue engineering applications, silk biomaterials have been increasingly utilized due to their biocompatibility, biological functions, and many favorable physical/chemical properties. Silk biomaterials are often used alone or in combination with other materials in the forms of patches or hydrogels, and serve as promising delivery systems for bioactive compounds in tissue engineering repair scenarios. This review focuses primarily on the promising characteristics of silk biomaterials and their recent advances in cardiac tissue engineering.

3D Cell Culture of Human Salivary Glands Using Nature-Inspired Functional Biomaterials: The Egg Yolk Plasma and Egg White

The egg yolk plasma (EYP)-a translucent fraction of the egg yolk (EY) obtained by centrifugation-was tested as a developmentally encouraging, cost-effective, biomaterial for salivary gland (SG) tissue engineering. To find optimal incubating conditions for both the human NS-SV-AC SG acinar cell line and SG fibroblasts, cells were stained with Live/Dead®. The cellular contents of 96-well plates were analyzed by high content screening image analysis. Characteristically, the EYP biomaterial had lipid and protein content resembling the EY. On its own, the EYP was non-conducive to cell survival. EYP's pH of 6 mainly contributed to cell death. This was demonstrated by titrating EYP's pH with different concentrations of either commercial cell culture media, NaOH, or egg white (EW). These additives improved SG mesenchymal and epithelial cell survival. The best combinations were EYP diluted with (1) 70% commercial medium, (2) 0.02 M NaOH, or (3) 50% EW. Importantly, commercial medium-free growth was obtained with EYP + NaOH or EYP + EW. Furthermore, 3D cultures were obtained as a result of EW's gelatinous properties. Here, the isolation, characterization, and optimization of three EYP-based biomaterial combinations are shown; two were free of commercial medium or supplements and supported both SG cells' survival.

Nanocomposite Gel as Injectable Therapeutic Scaffold: Microstructural Aspects and Bioactive Properties

The development of tissue scaffolds able to provide proper and accelerated regeneration of tissue is a main task of tissue engineering. We developed a nanocomposite gel that may be used as an injectable therapeutic scaffold. The nanocomposite gel is based on biocompatible gelling agents with embedded nanoparticles (iron oxide, silver, and hydroxyapatite) providing therapeutic properties. We have investigated the microstructure of the nanocomposite gel exposed to different substrates (porous materials and biological tissue). Here we show that the nanocomposite gel has the ability to self-reassemble mimicking the substrate morphology: exposition on porous mineral substrate caused reassembling of nanocomposite gel into 10× smaller scale structure; exposition to a section of humerus cortical bone decreased the microstructure scale more than twice (to ≤3 μm). The reassembling happens through a transitional layer which exists near the phase separation boundary. Our results impact the knowledge of gels explaining their abundance in biological organisms from the microstructural point of view. The results of our biological experiments showed that the nanocomposite gel may find diverse applications in the biomedical field.

The significance of artificial intelligence in drug delivery system design

Over the last decade, increasing interest has been attracted towards the application of artificial intelligence (AI) technology for analyzing and interpreting the biological or genetic information, accelerated drug discovery, and identification of the selective small-molecule modulators or rare molecules and prediction of their behavior. Application of the automated workflows and databases for rapid analysis of the huge amounts of data and artificial neural networks (ANNs) for development of the novel hypotheses and treatment strategies, prediction of disease progression, and evaluation of the pharmacological profiles of drug candidates may significantly improve treatment outcomes. Target fishing (TF) by rapid prediction or identification of the biological targets might be of great help for linking targets to the novel compounds. AI and TF methods in association with human expertise may indeed revolutionize the current theranostic strategies, meanwhile, validation approaches are necessary to overcome the potential challenges and ensure higher accuracy. In this review, the significance of AI and TF in the development of drugs and delivery systems and the potential challenging issues have been highlighted.

Comparative analysis of lncRNA and mRNA expression profiles between periodontal ligament stem cells and gingival mesenchymal stem cells

Oral tissue-derived mesenchymal stem cells, such as periodontal ligament stem cells (PDLSCs) and gingival mesenchymal stem cells (GMSCs), possess different biological characteristics, but the molecular mechanism remains unclear, which restricts their application in tissue engineering. Long noncoding RNAs (lncRNAs) are known to be significant regulators of gene expression, but our knowledge about their roles in the regulation of stem cell biological properties is still limited. This study compared the lncRNA and mRNA expression profiles between PDLSCs and GMSCs through microarray analysis, and applied bioinformatics methods to analyze and predict the function and connection of differentially expressed genes, aiming to screen potential key regulators of diverse biological characteristics in PDLSCs and GMSCs. Microarray analysis showed that 2162 lncRNAs and 1347 mRNAs were significantly differentially expressed between PDLSCs and GMSCs. Gene ontology (GO) analysis and pathway analysis indicated that these differentially expressed genes were involved in diverse biological processes and signaling pathways. The gene signal network and pathway relation network predicted some potentially important regulators. The coding-noncoding gene coexpression network (CNC network) revealed many potential lncRNA-mRNA connection pairs that participated in the regulation of biological behaviors. These results stressed the roles of lncRNAs in controlling stem cell biological behaviors and provided guides for molecular mechanistic study of different biological characteristics in PDLSCs and GMSCs.

Chondroitin sulfate-polydopamine modified polyethylene terephthalate with extracellular matrix-mimetic immunoregulatory functions for osseointegration

Optimal integration between the polyethylene terephthalate (PET) graft and host bone is a prerequisite to obtain a satisfactory outcome after graft implantation for ligament reconstruction.

Polysaccharide Based Scaffolds for Soft Tissue Engineering Applications

Soft tissue reconstructs require materials that form three-dimensional (3-D) structures supportive to cell proliferation and regenerative processes. Polysaccharides, due to their hydrophilicity, biocompatibility, biodegradability, abundance, and presence of derivatizable functional groups, are distinctive scaffold materials. Superior mechanical properties, physiological signaling, and tunable tissue response have been achieved through chemical modification of polysaccharides. Moreover, an appropriate formulation strategy enables spatial placement of the scaffold to a targeted site. With the advent of newer technologies, these preparations can be tailor-made for responding to alterations in temperature, pH, or other physiological stimuli. In this review, we discuss the developmental and biological aspects of scaffolds prepared from four polysaccharides, viz. alginic acid (ALG), chitosan (CHI), hyaluronic acid (HA), and dextran (DEX). Clinical studies on these scaffolds are also discussed.

Current Progress in 3D Bioprinting of Tissue Analogs

Tissue engineering has progressed tremendously over recent decades through the generation of functional tissue analogs. Traditional approaches based on seeding cells into scaffold are limited in their capacity to produce tissues with precise biomimetic properties. Three-dimensional (3D) bioprinting is one kind of fabrication technology used to precisely dispense cell-laden biomaterials for the construction of functional tissues or organs. In recent years, much research progress has been made in 3D bioprinting technology and its application in generating tissue analogs, including skin, heart valves, blood vessels, bone, and cardiac tissue. However, it still faces many technical challenges. In this review, we introduce the current progress in 3D bioprinting technology and focus on biomaterials and their potential applications in regenerative medicine and drug discovery. Current challenges are also discussed.