Role of Tissue Engineering in COVID-19 and Future Viral Outbreaks

An Infection Model for SARS-CoV-2 Using Rat Transplanted with hiPSC-Airway Epithelial Cells

Investigating the infection mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the airway epithelium and developing effective defense strategies against infection are important. To achieve this, establishing appropriate infection models is crucial. Therefore, various in vitro models, such as cell lines and primary cultures, and in vivo models involving animals that exhibit SARS-CoV-2 infection and genetically humanized animals have been used as animal models. However, no animal model has been established that allows infection experiments with human cells under the physiological environment of airway epithelia. Therefore, we aimed to establish a novel animal model that enables infection experiments using human cells. Human induced pluripotent stem cell-derived airway epithelial cell-transplanted nude rats (hiPSC-AEC rats) were used, and infection studies were performed by spraying lentiviral pseudoviruses containing SARS-CoV-2 spike protein and the GFP gene on the tracheae. After infection, immunohistochemical analyses revealed the existence of GFP-positive-infected transplanted cells in the epithelial and submucosal layers. In this study, a SARS-CoV-2 infection animal model including human cells was established mimicking infection through respiration, and we demonstrated that the hiPSC-AEC rat could be used as an animal model for basic research and the development of therapeutic methods for human-specific respiratory infectious diseases.

Engineering Materials and Devices for the Prevention, Diagnosis, and Treatment of COVID-19 and Infectious Diseases

Following the global spread of COVID-19, scientists and engineers have adapted technologies and developed new tools to aid in the fight against COVID-19. This review discusses various approaches to engineering biomaterials, devices, and therapeutics, especially at micro and nano levels, for the prevention, diagnosis, and treatment of infectious diseases, such as COVID-19, serving as a resource for scientists to identify specific tools that can be applicable for infectious-disease-related research, technology development, and treatment. From the design and production of equipment critical to first responders and patients using three-dimensional (3D) printing technology to point-of-care devices for rapid diagnosis, these technologies and tools have been essential to address current global needs for the prevention and detection of diseases. Moreover, advancements in organ-on-a-chip platforms provide a valuable platform to not only study infections and disease development in humans but also allow for the screening of more effective therapeutics. In addition, vaccines, the repurposing of approved drugs, biomaterials, drug delivery, and cell therapy are promising approaches for the prevention and treatment of infectious diseases. Following a comprehensive review of all these topics, we discuss unsolved problems and future directions.

In vitro high-content tissue models to address precision medicine challenges

The field of precision medicine allows for tailor-made treatments specific to a patient and thereby improve the efficiency and accuracy of disease prevention, diagnosis, and treatment and at the same time would reduce the cost, redundant treatment, and side effects of current treatments. Here, the combination of organ-on-a-chip and bioprinting into engineering high-content in vitro tissue models is envisioned to address some precision medicine challenges. This strategy could be employed to tackle the current coronavirus disease 2019 (COVID-19), which has made a significant impact and paradigm shift in our society. Nevertheless, despite that vaccines against COVID-19 have been successfully developed and vaccination programs are already being deployed worldwide, it will likely require some time before it is available to everyone. Furthermore, there are still some uncertainties and lack of a full understanding of the virus as demonstrated in the high number new mutations arising worldwide and reinfections of already vaccinated individuals. To this end, efficient diagnostic tools and treatments are still urgently needed. In this context, the convergence of bioprinting and organ-on-a-chip technologies, either used alone or in combination, could possibly function as a prominent tool in addressing the current pandemic. This could enable facile advances of important tools, diagnostics, and better physiologically representative in vitro models specific to individuals allowing for faster and more accurate screening of therapeutics evaluating their efficacy and toxicity. This review will cover such technological advances and highlight what is needed for the field to mature for tackling the various needs for current and future pandemics as well as their relevancy towards precision medicine.

Market of tissue engineering in Canada from 2011 to 2020

Tissue engineering aims to produce tissue/organ substitutes to improve upon current treatment approaches, thus providing a permanent solution to damaged tissues/organs. This project aimed to perform a market analysis for understanding and promoting the development and commercialization of tissue engineering in Canada. We searched companies that were established between October 2011 and July 2020 via publicly available information and for these companies, we collected and analyzed the corporate level information, including revenues, and number of employees and founder information. The companies assessed were mainly searched from four different industry segments, i.e., bioprinting, biomaterials, cells and biomaterials, and stem-cells related industry. Our results have demonstrated that there are twenty-five tissue-engineering companies registered in Canada. These companies generated an estimated revenue of USD $67 million in the year 2020, most generated by the tissue engineering and stem-cells related industries. Our results also show that Ontario has the largest number of headquarters of tissue engineering companies among the provinces or territories of Canada. It is expected that the number of new products undergoing clinical trials is increased, based on our results of current clinical trials. Altogether, tissue engineering in Canada has shown a huge growth in the past decade and is forecasted to be an emerging industry in Canada for the years to come.

Engineering organ-on-a-chip systems to model viral infections

Infectious diseases remain a public healthcare concern worldwide. Amidst the pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 infection, increasing resources have been diverted to investigate therapeutics targeting the COVID-19 spike glycoprotein and to develop various classes of vaccines. Most of the current investigations employ two-dimensional (2D) cell culture and animal models. However, 2D culture negates the multicellular interactions and three-dimensional (3D) microenvironment, and animal models cannot mimic human physiology because of interspecies differences. On the other hand, organ-on-a-chip (OoC) devices introduce a game-changer to model viral infections in human tissues, facilitating high-throughput screening of antiviral therapeutics. In this context, this review provides an overview of thein vitroOoC-based modeling of viral infection, highlighting the strengths and challenges for the future.

COVID-19 surveillance in wastewater: An epidemiological tool for the monitoring of SARS-CoV-2

The coronavirus disease 2019 (COVID-19) pandemic has prompted a lot of questions globally regarding the range of information about the virus's possible routes of transmission, diagnostics, and therapeutic tools. Worldwide studies have pointed out the importance of monitoring and early surveillance techniques based on the identification of viral RNA in wastewater. These studies indicated the presence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in human feces, which is shed via excreta including mucus, feces, saliva, and sputum. Subsequently, they get dumped into wastewater, and their presence in wastewater provides a possibility of using it as a tool to help prevent and eradicate the virus. Its monitoring is still done in many regions worldwide and serves as an early "warning signal"; however, a lot of limitations of wastewater surveillance have also been identified.

Biomimetic lung-on-a-chip to model virus infection and drug evaluation

Viral infectious diseases remain a global public health problem. The rapid and widespread spread of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV‑2) has had a severe impact on the global economy and human activities, highlighting the vulnerability of humans to viral infectious diseases and the urgent need to develop new technologies and effective treatments. Organ-on-a-chip is an emerging technology for constructing the physiological and pathological microenvironment of human organs in vitro and has the advantages of portability, high throughput, low cost, and accurate simulation of the in vivo microenvironment. Indeed, organ-on-a-chip provides a low-cost alternative for investigating human organ physiology, organ diseases, toxicology, and drug efficacy. The lung is a main target organ of viral infection, and lung pathophysiology must be assessed after viral infection and treatment with antiviral drugs. This review introduces the construction of lung-on-a-chip and its related pathophysiological models, focusing on the in vitro simulation of viral infection and evaluation of antiviral drugs, providing a developmental direction for research and treatment of viral diseases.

Viral and non-viral gene therapy using 3D (bio)printing

The overall success in launching discovered drugs is tightly restricted to the high rate of late-stage failures, which ultimately inhibits the distribution of medicines in markets. As a result, it is imperative that methods reliably predict the effectiveness and, more critically, the toxicity of medicine early in the drug development process before clinical trials be continuously innovated. We must stay up to date with the fast appearance of new infections and diseases by rapidly developing the requisite vaccinations and medicines. Modern in vitro models of disease may be used as an alternative to traditional disease models, and advanced technology can be used for the creation of pharmaceuticals as well as cells, drugs, and gene delivery systems to expedite the drug discovery procedure. Furthermore, in vitro models that mimic the spatial and chemical characteristics of native tissues, such as a 3D bioprinting system or other technologies, have proven to be more effective for drug screening than traditional 2D models. Viral and non-viral gene delivery vectors are a hopeful tool for combinatorial gene therapy, suggesting a quick way of simultaneously deliver multiple genes. A 3D bioprinting system embraces an excellent potential for gene delivery into the different cells or tissues for different diseases, in tissue engineering and regeneration medicine, in which the precise nucleic acid is located in the 3D printed tissues and scaffolds. Non-viral nanocarriers, in combination with 3D printed scaffolds, are applied to their delivery of genes and controlled release properties. There remains, however, a big obstacle in reaching the full potential of 3D models because of a lack of in vitro manufacturing of live tissues. Bioprinting advancements have made it possible to create biomimetic constructions that may be used in various drug discovery research applications. 3D bioprinting also benefits vaccinations, medicines, and relevant delivery methods because of its flexibility and adaptability. This review discusses the potential of 3D bioprinting technologies for pharmaceutical studies.

Biomaterials for Tissue Engineering Applications and Current Updates in the Field: A Comprehensive Review

Tissue engineering has emerged as an interesting field nowadays; it focuses on accelerating the auto-healing mechanism of tissues rather than organ transplantation. It involves implanting an In Vitro cultured initiative tissue or a scaffold loaded with tissue regenerating ingredients at the damaged area. Both techniques are based on the use of biodegradable, biocompatible polymers as scaffolding materials which are either derived from natural (e.g. alginates, celluloses, and zein) or synthetic sources (e.g. PLGA, PCL, and PLA). This review discusses in detail the recent applications of different biomaterials in tissue engineering highlighting the targeted tissues besides the in vitro and in vivo key findings. As well, smart biomaterials (e.g. chitosan) are fascinating candidates in the field as they are capable of elucidating a chemical or physical transformation as response to external stimuli (e.g. temperature, pH, magnetic or electric fields). Recent trends in tissue engineering are summarized in this review highlighting the use of stem cells, 3D printing techniques, and the most recent 4D printing approach which relies on the use of smart biomaterials to produce a dynamic scaffold resembling the natural tissue. Furthermore, the application of advanced tissue engineering techniques provides hope for the researchers to recognize COVID-19/host interaction, also, it presents a promising solution to rejuvenate the destroyed lung tissues.

Combination of polyglycerol sebacate coated with collagen for vascular engineering

Introduction: Here, we monitored the cytocompatibility of scaffolds consisting of poly (glycerol sebacate) (PGS) coated with collagen (Col) for endothelial cell activity after 72 hours. Methods: Human endothelial cells were allocated into Control, PGS, and PGS+Col groups. Scaffolds were characterized using FTIR and HNMR spectroscopy. Contact angel analysis and SEM were used to study wettability, surface morphology, and cell attachment. Cell survival was assessed using LDH leakage assay. Levels of Tie-1, Tie-2, VE-Cadherin, and VEGFR-2 were measured using western blotting and real-time PCR. Results: FTIR and HNMR analyses revealed the proper blending in PGS+Col group. SEM imaging exhibited a flat surface in the PGS group while thin Col fibers were detected in PGS+Col surface. The addition of Col to the PGS reduced the contract angle values from 97.3˚ to 81.1˚. Compared to PGS substrate alone, in PGS+Col group, cells appropriately attached to the surface. PGS and PGS+Col did not alter the leakage of LDH to the supernatant compared to control cells, showing the cytocopatiblity of PGS-based scaffolds. SOD and NO levels were increased significantly in PGS (p<0.05) and PGS+Col groups (p<0.001), respectively. We found that PGS+Col decreased Tie-1 content in endothelial cells whereas protein levels of Tie-2 and VE-Cadherin and expression of VEGFR-2 remained unchanged compared to PGS and control groups. Conclusion: Simultaneous application of Col and PGS can stimulate normal endothleial cell morphology without the alteration of tyrosine kinases receptors and cadherin.

Engineering viral genomics and nano-liposomes in microfluidic platforms for patient-specific analysis of SARS-CoV-2 variants

New variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are continuing to spread globally, contributing to the persistence of the COVID-19 pandemic. Increasing resources have been focused on developing vaccines and therapeutics that target the Spike glycoprotein of SARS-CoV-2. Recent advances in microfluidics have the potential to recapitulate viral infection in the organ-specific platforms, known as organ-on-a-chip (OoC), in which binding of SARS-CoV-2 Spike protein to the angiotensin-converting enzyme 2 (ACE2) of the host cells occurs. As the COVID-19 pandemic lingers, there remains an unmet need to screen emerging mutations, to predict viral transmissibility and pathogenicity, and to assess the strength of neutralizing antibodies following vaccination or reinfection. Conventional detection of SARS-CoV-2 variants relies on two-dimensional (2-D) cell culture methods, whereas simulating the micro-environment requires three-dimensional (3-D) systems. To this end, analyzing SARS-CoV-2-mediated pathogenicity via microfluidic platforms minimizes the experimental cost, duration, and optimization needed for animal studies, and obviates the ethical concerns associated with the use of primates. In this context, this review highlights the state-of-the-art strategy to engineer the nano-liposomes that can be conjugated with SARS-CoV-2 Spike mutations or genomic sequences in the microfluidic platforms; thereby, allowing for screening the rising SARS-CoV-2 variants and predicting COVID-19-associated coagulation. Furthermore, introducing viral genomics to the patient-specific blood accelerates the discovery of therapeutic targets in the face of evolving viral variants, including B1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta), c.37 (Lambda), and B.1.1.529 (Omicron). Thus, engineering nano-liposomes to encapsulate SARS-CoV-2 viral genomic sequences enables rapid detection of SARS-CoV-2 variants in the long COVID-19 era.

Breakthroughs and Applications of Organ-on-a-Chip Technology

Organ-on-a-chip (OOAC) is an emerging technology based on microfluid platforms and in vitro cell culture that has a promising future in the healthcare industry. The numerous advantages of OOAC over conventional systems make it highly popular. The chip is an innovative combination of novel technologies, including lab-on-a-chip, microfluidics, biomaterials, and tissue engineering. This paper begins by analyzing the need for the development of OOAC followed by a brief introduction to the technology. Later sections discuss and review the various types of OOACs and the fabrication materials used. The implementation of artificial intelligence in the system makes it more advanced, thereby helping to provide a more accurate diagnosis as well as convenient data management. We introduce selected OOAC projects, including applications to organ/disease modelling, pharmacology, personalized medicine, and dentistry. Finally, we point out certain challenges that need to be surmounted in order to further develop and upgrade the current systems.

Regenerative Endodontics and Minimally Invasive Dentistry: Intertwining Paths Crossing Over Into Clinical Translation

Regenerative endodontic procedures have been described for over a decade as a paradigm shift in the treatment of immature necrotic permanent teeth, owing to their ability to allow root maturation with subsequent enhancement of the tooth’s fracture resistance in addition to the potential for regeneration of vital intracanal tissues. Concomitantly, minimally invasive endodontics is another rising concept with the main concern of preservation of tooth structure. Stemming from their potential to preserve the original tooth structure, both regenerative and minimally invasive endodontics could be considered as two revolutionary sciences with one common goal. Achieving this goal would entail not only employing the appropriate strategies to recreate the ideal regenerative niche but modifying existing concepts and protocols currently being implemented in regenerative endodontics to address two important challenges affecting the outcome of these procedures; conservation of tooth structure and achieving effective disinfection. Therefore, the search for new biomimetic cell-friendly disinfecting agents and strategies is crucial if such a novel integratory concept is to be foreseen in the future. This could be attainable by advocating a new merged concept of “minimally invasive regenerative endodontic procedures (MIREPs),” through modifying the clinical protocol of REPs by incorporating a minimally invasive access cavity design/preparation and biomimetic disinfection protocol, which could enhance clinical treatment outcomes and in the future; allow for personalized disinfection/regeneration protocols to further optimize the outcomes of MIREPs. In this review, we aim to introduce this new concept, its realization and challenges along with future perspectives for clinical implementation.

Modeling viral infection with tissue engineering: COVID-19 and the next outbreaks

Pandemics caused by respiratory viruses have impacted millions of lives and caused massive destruction to global infrastructure. With their emergence, it has become a priority to develop platforms to rapidly dissect host/pathogen interactions, develop diagnostics, and evaluate therapeutics. Traditional viral culture methods do not faithfully recapitulate key aspects of infection. Tissue engineering as a discipline has developed techniques to produce three-dimensional human tissues which can serve as platforms to study respiratory viruses in vitro. In this chapter, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been used as a representative respiratory virus motivating the use of tissue engineering to generate in vitro culture models. SARS-CoV-2 pathophysiology, traditional cell culture, tissue engineering-based cell culture, and future directions for the field are highlighted.

Exploiting the role of nanoparticles for use in hydrogel-based bioprinting applications: concept, design, and recent advances

Three-dimensional (3D) bioprinting is an emerging tissue engineering approach that aims to develop cell or biomolecule-laden, complex polymeric scaffolds with high precision, using hydrogel-based "bioinks". Hydrogels are water-swollen, highly crosslinked polymer networks that are soft, quasi-solid, and can support and protect biological materials. However, traditional hydrogels have weak mechanical properties and cannot retain complex structures. They must be reinforced with physical and chemical manipulations to produce a mechanically resilient bioink. Over the past few years, we have witnessed an increased use of nanoparticles and biological moiety-functionalized nanoparticles to fabricate new bioinks. Nanoparticles of varied size, shape, and surface chemistries can provide a unique solution to this problem primarily because of three reasons: (a) nanoparticles can mechanically reinforce hydrogels through physical and chemical interactions. This can favorably influence the bioink's 3D printability and structural integrity by modulating its rheological, biomechanical, and biochemical properties, allowing greater flexibility to print a wide range of structures; (b) nanoparticles can introduce new bio-functionalities to the hydrogels, which is a key metric of a bioink's performance, influencing both cell-material and cell-cell interactions within the hydrogel; (c) nanoparticles can impart "smart" features to the bioink, making the tissue constructs responsive to external stimuli. Responsiveness of the hydrogel to magnetic field, electric field, pH changes, and near-infrared light can be made possible by the incorporation of nanoparticles. Additionally, bioink polymeric networks with nanoparticles can undergo advanced chemical crosslinking, allowing greater flexibility to print structures with varied biomechanical properties. Taken together, the unique properties of various nanoparticles can help bioprint intricate constructs, bringing the process one step closer to complex tissue structure and organ printing. In this review, we explore the design principles and multifunctional properties of various nanomaterials and nanocomposite hydrogels for potential, primarily extrusion-based bioprinting applications. We illustrate the significance of biocompatibility of the designed nanocomposite hydrogel-based bioink for clinical translation and discuss the different parameters that affect cell fate after cell-nanomaterial interaction. Finally, we critically assess the current challenges of nanoengineering bioinks and provide insight into the future directions of potential hydrogel bioinks in the rapidly evolving field of bioprinting.

3D printing technologies for in vitro vaccine testing platforms and vaccine delivery systems against infectious diseases

Recent advances in 3D printing (3DP) and tissue engineering approaches enable the potential application of these technologies to vaccine research. Reconstituting the native tissue or cellular microenvironment will be vital for successful evaluation of pathogenicity of viral infection and screening of potential vaccines. Therefore, establishing a reliable in vitro model to study the vaccine efficiency or delivery of viral disease is important. Here, this review summarizes two major ways that tissue engineering and 3DP strategies could contribute to vaccine research: (1) 3D human tissue models to study the response to virus can be served as a testbed for new potential therapeutics. Using 3D tissue platform attempts to explore alternative options to pre-clinical animal research for evaluating vaccine candidates. (2) 3DP technologies can be applied to improve the vaccination strategies which could replace existing vaccine delivery. Controlled antigen release using carriers that are generated with biodegradable biomaterials can further enhance the efficient development of immunity as well as combination of multiple-dose vaccines into a single injection. This mini review discusses the up-to-date report of current 3D tissue/organ models for potential vaccine potency and known bioengineered vaccine delivery systems.

COVID-19 Impact on Musculoskeletal Regenerative Medicine Research: Maintaining Lab Continuity

BACKGROUND

Research in the fields of musculoskeletal tissue engineering and regenerative medicine may suffer a slowdown during the ongoing COVID-19 pandemic emergency. This is likely to harm the development of new therapeutic strategies and their translation into the clinic in the long term. Recently, the need to maintain continuity in research activities in those fields has assumed even greater importance due to the accumulation of data concerning the effects of SARS-CoV-2 on the musculoskeletal system. This study is aimed at the identification of a series of safe handling practices against COVID-19 diffusion to apply in a research environment, thus allowing the maintenance of research lab activities.

METHODS

The control measures to apply to mitigate the COVID-19 risk were identified and categorized utilizing the Hierarchy of Controls. We also compared our analysis with that assessed before the pandemic to consider the additional risk of COVID-19.

RESULTS

Results highlighted that the most relevant implemented measures to control SARS-CoV-2 were based on protecting people through engineering (e.g., ventilation and social distancing), and administrative (e.g., hand sanitization, work shifts) measures or Personnel Protective Equipment, rather than eliminating hazards at the source (e.g., smart working).

CONCLUSIONS

Work continuity in research labs during the COVID-19 emergency should be guaranteed by ensuring the protection of researchers in the workplace and considering the physical environment, the type of operators and work activity, and the proven ability of workers to face biological risks. The increased knowledge and awareness on lab' risks should be useful to prevent and mitigate future viral outbreaks.

Biomaterials-Based Opportunities to Engineer the Pulmonary Host Immune Response in COVID-19

The COVID-19 pandemic caused by the global spread of the SARS-CoV-2 virus has led to a staggering number of deaths worldwide and significantly increased burden on healthcare as nations scramble to find mitigation strategies. While significant progress has been made in COVID-19 diagnostics and therapeutics, effective prevention and treatment options remain scarce. Because of the potential for the SARS-CoV-2 infections to cause systemic inflammation and multiple organ failure, it is imperative for the scientific community to evaluate therapeutic options aimed at modulating the causative host immune responses to prevent subsequent systemic complications. Harnessing decades of expertise in the use of natural and synthetic materials for biomedical applications, the biomaterials community has the potential to play an especially instrumental role in developing new strategies or repurposing existing tools to prevent or treat complications resulting from the COVID-19 pathology. Leveraging microparticle- and nanoparticle-based technology, especially in pulmonary delivery, biomaterials have demonstrated the ability to effectively modulate inflammation and may be well-suited for resolving SARS-CoV-2-induced effects. Here, we provide an overview of the SARS-CoV-2 virus infection and highlight current understanding of the host's pulmonary immune response and its contributions to disease severity and systemic inflammation. Comparing to frontline COVID-19 therapeutic options, we highlight the most significant untapped opportunities in immune engineering of the host response using biomaterials and particle technology, which have the potential to improve outcomes for COVID-19 patients, and identify areas needed for future investigations. We hope that this work will prompt preclinical and clinical investigations of promising biomaterials-based treatments to introduce new options for COVID-19 patients.

Bioengineering Technology in Context of COVID-19 Pandemic: Potential Roles and Applications

Bioengineering (BE) technology has significant influence on the healthcare environment. This has grown steadily particularly since the medical practice has become more technology based. We have tried to assess the impact of bioengineering in tackling the COVID-19 pandemic. The use of bioengineering principles in healthcare has been evaluated. The practical implications of these technologies in fighting the current global health pandemic have been presented. There has been a shared drive worldwide to harness the advancements of bioengineering to combat COVID-19. These efforts have ranged from small groups of volunteers to large scale research and mass production. Together the engineering and medical fields have worked to address areas of critical need including the production and delivery of personal protective equipment, ventilators as well as the creation of a viable vaccine. The fight against COVID-19 has helped highlight the work and contributions of so many professionals in the bioengineering fields who are working tirelessly to help our health services cope. Their innovation and ingenuity are paving the way to successfully beat this virus. We must continue to support these fields as we evolve our health systems to deal with the challenges of healthcare in the future.

Role of biomaterials in the diagnosis, prevention, treatment, and study of corona virus disease 2019 (COVID-19)

Recently emerged novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the resulting corona virus disease 2019 (COVID-19) led to urgent search for methods to prevent and treat COVID-19. Among important disciplines that were mobilized is the biomaterials science and engineering. Biomaterials offer a range of possibilities to develop disease models, protective, diagnostic, therapeutic, monitoring measures, and vaccines. Among the most important contributions made so far from this field are tissue engineering, organoids, and organ-on-a-chip systems, which have been the important frontiers in developing tissue models for viral infection studies. Also, due to low bioavailability and limited circulation time of conventional antiviral drugs, controlled and targeted drug delivery could be applied alternatively. Fortunately, at the time of writing this paper, we have two successful vaccines and new at-home detection platforms. In this paper, we aim to review recent advances of biomaterial-based platforms for protection, diagnosis, vaccination, therapeutics, and monitoring of SARS-CoV-2 and discuss challenges and possible future research directions in this field.

3D Bioprinting of In Vitro Models Using Hydrogel-Based Bioinks

Coronavirus disease 2019 (COVID-19), which has recently emerged as a global pandemic, has caused a serious economic crisis due to the social disconnection and physical distancing in human society. To rapidly respond to the emergence of new diseases, a reliable in vitro model needs to be established expeditiously for the identification of appropriate therapeutic agents. Such models can be of great help in validating the pathological behavior of pathogens and therapeutic agents. Recently, in vitro models representing human organs and tissues and biological functions have been developed based on high-precision 3D bioprinting. In this paper, we delineate an in-depth assessment of the recently developed 3D bioprinting technology and bioinks. In particular, we discuss the latest achievements and future aspects of the use of 3D bioprinting for in vitro modeling.

The role of biomaterials and three dimensional (3D) in vitro tissue models in fighting against COVID-19

Over the past century, viral respiratory pandemics have been a leading cause of infectious disease worldwide. A deep understanding of the underlying mechanisms of the viral interactions with host cells at the target sites is necessary for a rapid response to such pandemics. To meet this aim, various testing platforms are required to recapitulate the pathophysiological behavior of the virus within the respiratory tract. These bioengineered platforms can effectively be used for the development of different therapeutics and vaccines. This paper briefly reviews the progress in the areas of biomaterial use for pulmonary tissue regeneration and integration with current bioengineered platforms including engineered tissues, organoids, and organs-on-a-chip platforms for viral respiratory disease studies. Finally, a brief overview of the opportunities presented by organ-on-a-chip systems for studying COVID-19 and subsequent drug development is introduced.

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.

Bioprinting for combating infectious diseases

Infectious diseases have the ability to impact health on a global scale, as is being demonstrated by the current coronavirus disease 2019 (COVID-19) pandemic. The strenuous circumstances related to this global health crisis have been highlighting the challenges faced by the biomedical field in combating infectious diseases. Notably, printing technologies have advanced rapidly over the last decades, allowing for the incorporation of living cells in the printing process (or bioprinting) to create constructs that are able to serve as in vitro tissue or virus-disease models in combating infectious diseases. This paper describes applications of bioprinting in addressing the challenges faced in combating infectious diseases, with a specific focus on in vitro modelling and on development of therapeutic agents and vaccines. Integration of these technologies may allow for a more efficient and effective response to current and future pandemics.

Combating COVID-19 with tissue engineering: a review

The ongoing COVID-19 pandemic triggered by SARS-CoV-2 emerged from Wuhan, China, firstly in December 2019, as well spread to almost all around the world rapidly. The main reason why this disease spreads so many people in a short time is that the virus could be transmitted from an infected person to another by infected droplets. The new emergence of diseases usually may affect multiple organs; moreover, this disease is such an example. Numerous reported studies focus on acute or chronic organ damage caused by the virus. At this point, tissue engineering (TE) strategies can be used to treat the damages with its interdisciplinary approaches. Tissue engineers could design drug delivery systems, scaffolds, and especially biomaterials for the damaged tissue and organs. In this review, brief information about SARS-CoV-2, COVID-19, and epidemiology of the disease will be given at first. After that, the symptoms, the tissue damages in specific organs, and cytokine effect caused by COVID-19 will be described in detail. Finally, it will be attempted to summarize and suggest the appropriate treatments with suitable biomaterials for the damages via TE approaches. The aim of this review is to serve as a summary of currently available tissue damage treatments after COVID-19.

Highlights in Mesoporous Silica Nanoparticles as a Multifunctional Controlled Drug Delivery Nanoplatform for Infectious Diseases Treatment

Infectious diseases are a major global concern being responsible for high morbidity and mortality mainly due to the development and enhancement of multidrug-resistant microorganisms exposing the fragility of medicines and vaccines commonly used to these treatments. Taking into account the scarcity of effective formulation to treat infectious diseases, nanotechnology offers a vast possibility of ground-breaking platforms to design new treatment through smart nanostructures for drug delivery purposes. Among the available nanosystems, mesoporous silica nanoparticles (MSNs) stand out due their multifunctionality, biocompatibility and tunable properties make them emerging and actual nanocarriers for specific and controlled drug release. Considering the high demand for diseases prevention and treatment, this review exploits the MSNs fabrication and their behavior in biological media besides highlighting the most of strategies to explore the wide MSNs functionality as engineered, smart and effective controlled drug release nanovehicles for infectious diseases treatment. Graphical Abstract Schematic representation of multifunctional MSNs-based nanoplatforms for infectious diseases treatment.

Coronavirus disease 2019: A tissue engineering and regenerative medicine perspective

Current therapies for novel coronavirus disease (COVID‐19) are generally used to manage rather than cure this highly infective disease. Therefore, there is a significant unmet medical need for a safe and effective treatment for COVID‐19. Inflammation is the driving force behind coronavirus infections, and the majority of deaths caused by COVID‐19 are the result of acute respiratory distress syndrome (ARDS). It is crucial to control the inflammation as early as possible. To date, numerous studies have been conducted to evaluate the safety and efficacy of tissue engineering and regenerative medicine (TERM) products, including mesenchymal stem cells (MSCs), and their derivatives (eg, exosomes) for coronavirus infections, which could be applied for the COVID‐19. In this review, first, the impacts of the COVID‐19 pandemic in the present and future of TERM research and products are briefly presented. Then, the recent clinical trials and the therapeutic benefits of MSCs in coronavirus‐induced ARDS are critically reviewed. Last, recent advances in the field of tissue engineering relevant to coronavirus infections, including three‐dimensional platforms to study the disease progression and test the effects of antiviral agents, are described. Moreover, the application of biomaterials for vaccine technology and drug delivery are highlighted. Despite promising results in the preclinical and clinical applications of MSC therapy for coronavirus infections, controversy still exists, and thus further investigation is required to understand the efficacy of these therapies.