A facile technique to develop conductive paper based bioelectrodes for microbial fuel cell applications.

Electronic devices with multifunctional capabilities is forever an attractive area with diverse scope including towards developing solutions to sustainable energy technology. Microbial biofuel cells (MiBFCs) are one such sustainable energy technology based electronic device which can not only harvest energy, but can perform biosensing leading to bioremediation. However, low energy yield, costly fabrication procedures and bulky devices are some of the limitations of such MiBFCs. In this work, for the first time a simple vacuum filtration fabrication technique is used for making thin and conductive electrodes with homogeneous CNT solution for MiBFC application. The fully paper-based MiBFC is integrated into a compact micro device with 3D printed components which adds novelty to the work. The MiBFC is capable of maintaining a stable open circuit voltage of 410 mV for more than 1 h and can deliver a maximum power density of 192 µW/cm2 which is reasonably high for such paper-based MiBFCs operating with micro-volume of substrate. This device will help in developing more freestanding power sources for instant diagnostics and data transfer.

An exploration of the use of 3D printed foot models and simulated foot lesions to supplement scalpel skill training in undergraduate podiatry students: A multiple method study.

BACKGROUND: Podiatrists regularly use scalpels in the management of foot pathologies, yet the teaching and learning of these skills can be challenging. The use of 3D printed foot models presents an opportunity for podiatry students to practice their scalpel skills in a relatively safe, controlled risk setting, potentially increasing confidence and reducing associated anxiety. This study evaluated the use of 3D printed foot models on podiatry students' anxiety and confidence levels and explored the fidelity of using 3D foot models as a teaching methodology. MATERIALS AND METHODS: Multiple study designs were used. A repeated measure trial evaluated the effects of a 3D printed foot model on anxiety and confidence in two student groups: novice users in their second year of podiatry studies (n = 24), and more experienced fourth year students completing a workshop on ulcer management (n = 15). A randomised controlled trial compared the use of the 3D printed foot models (n = 12) to standard teaching methods (n = 15) on students' anxiety and confidence in second year students. Finally, a focus group was conducted (n = 5) to explore final year student's perceptions of the fidelity of the foot ulcer models in their studies. RESULTS: The use of 3D printed foot models increased both novice and more experienced users' self-confidence and task self-efficacy; however, cognitive and somatic anxiety was only reduced in the experienced users. All changes were considered large effects. In comparison to standard teaching methods, the use of 3D printed foot models had similar decreases in anxiety and increases in confidence measures. Students also identified the use of 3D foot models for the learning of scalpel skills as 'authentic' and 'lifelike' and led to enhanced confidence prior to assessment of skills in more high-risk situations. CONCLUSION: Podiatry undergraduate programs should consider using 3D printed foot models as a teaching method to improve students' confidence and reduce their anxiety when using scalpels, especially in instances where face-to-face teaching is not possible (e.g., pandemic related restrictions on face-to-face teaching).

Research progress on the biological modifications of implant materials in 3D printed intervertebral fusion cages.

Anterior spine decompression and reconstruction with bone grafts and fusion is a routine spinal surgery. The intervertebral fusion cage can maintain intervertebral height and provide a bone graft window. Titanium fusion cages are the most widely used metal material in spinal clinical applications. However, there is a certain incidence of complications in clinical follow-ups, such as pseudoarticulation formation and implant displacement due to nonfusion of bone grafts in the cage. With the deepening research on metal materials, the properties of these materials have been developed from being biologically inert to having biological activity and biological functionalization, promoting adhesion, cell differentiation, and bone fusion. In addition, 3D printing, thin-film, active biological material, and 4D bioprinting technology are also being used in the biofunctionalization and intelligent advanced manufacturing processes of implant devices in the spine. This review focuses on the biofunctionalization of implant materials in 3D printed intervertebral fusion cages. The surface modifications of implant materials in metal endoscopy, material biocompatibility, and bioactive functionalizationare summarized. Furthermore, the prospects and challenges of the biofunctionalization of implant materials in spinal surgery are discussed. Fig.a.b.c.d.e.f.g As a pre-selected image for the cover, I really look forward to being selected. Special thanks to you for your comments.

3D Bio-Printability of Hybrid Pre-Crosslinked Hydrogels.

Maintaining shape fidelity of 3D bio-printed scaffolds with soft biomaterials is an ongoing challenge. Here, a rheological investigation focusing on identifying useful physical and mechanical properties directly related to the geometric fidelity of 3D bio-printed scaffolds is presented. To ensure during- and post-printing shape fidelity of the scaffolds, various percentages of Carboxymethyl Cellulose (CMC) (viscosity enhancer) and different calcium salts (CaCl2 and CaSO4, physical cross-linkers) were mixed into alginate before extrusion to realize shape fidelity. The overall solid content of Alginate-Carboxymethyl Cellulose (CMC) was limited to 6%. A set of rheological tests, e.g., flow curves, amplitude tests, and three interval thixotropic tests, were performed to identify and compare the shear-thinning capacity, gelation points, and recovery rate of various compositions. The geometrical fidelity of the fabricated scaffolds was defined by printability and collapse tests. The effect of using multiple cross-linkers simultaneously was assessed. Various large-scale scaffolds were fabricated (up to 5.0 cm) using a pre-crosslinked hybrid. Scaffolds were assessed for the ability to support the growth of Escherichia coli using the Most Probable Number technique to quantify bacteria immediately after inoculation and 24 h later. This pre-crosslinking-based rheological property controlling technique can open a new avenue for 3D bio-fabrication of scaffolds, ensuring proper geometry.

3D bioprinting in cardiac tissue engineering.

Heart disease is the main cause of death worldwide. Because death of the myocardium is irreversible, it remains a significant clinical challenge to rescue myocardial deficiency. Cardiac tissue engineering (CTE) is a promising strategy for repairing heart defects and offers platforms for studying cardiac tissue. Numerous achievements have been made in CTE in the past decades based on various advanced engineering approaches. 3D bioprinting has attracted much attention due to its ability to integrate multiple cells within printed scaffolds with complex 3D structures, and many advancements in bioprinted CTE have been reported recently. Herein, we review the recent progress in 3D bioprinting for CTE. After a brief overview of CTE with conventional methods, the current 3D printing strategies are discussed. Bioink formulations based on various biomaterials are introduced, and strategies utilizing composite bioinks are further discussed. Moreover, several applications including heart patches, tissue-engineered cardiac muscle, and other bionic structures created via 3D bioprinting are summarized. Finally, we discuss several crucial challenges and present our perspective on 3D bioprinting techniques in the field of CTE.

Extrusion Based 3D Printing of Sustainable Biocomposites from Biocarbon and Poly(trimethylene terephthalate).

Three-dimensional (3D) printing manufactures intricate computer aided designs without time and resource spent for mold creation. The rapid growth of this industry has led to its extensive use in the automotive, biomedical, and electrical industries. In this work, biobased poly(trimethylene terephthalate) (PTT) blends were combined with pyrolyzed biomass to create sustainable and novel printing materials. The Miscanthus biocarbon (BC), generated from pyrolysis at 650 °C, was combined with an optimized PTT blend at 5 and 10 wt % to generate filaments for extrusion 3D printing. Samples were printed and analyzed according to their thermal, mechanical, and morphological properties. Although there were no significant differences seen in the mechanical properties between the two BC composites, the optimal quantity of BC was 5 wt % based upon dimensional stability, ease of printing, and surface finish. These printable materials show great promise for implementation into customizable, non-structural components in the electrical and automotive industries.

Advances in tissue engineering of vasculature through three-dimensional bioprinting.

BACKGROUND: A significant challenge facing tissue engineering is the fabrication of vasculature constructs which contains vascularized tissue constructs to recapitulate viable, complex and functional organs or tissues, and free-standing vascular structures potentially providing clinical applications in the future. Three-dimensional (3D) bioprinting has emerged as a promising technology, possessing a number of merits that other conventional biofabrication methods do not have. Over the last decade, 3D bioprinting has contributed a variety of techniques and strategies to generate both vascularized tissue constructs and free-standing vascular structures. RESULTS: This review focuses on different strategies to print two kinds of vasculature constructs, namely vascularized tissue constructs and vessel-like tubular structures, highlighting the feasibility and shortcoming of the current methods for vasculature constructs fabrication. Generally, both direct printing and indirect printing can be employed in vascularized tissue engineering. Direct printing allows for structural fabrication with synchronous cell seeding, while indirect printing is more effective in generating complex architecture. During the fabrication process, 3D bioprinting techniques including extrusion bioprinting, inkjet bioprinting and light-assisted bioprinting should be selectively implemented to exert advantages and obtain the desirable tissue structure. Also, appropriate cells and biomaterials matter a lot to match various bioprinting techniques and thus achieve successful fabrication of specific vasculature constructs. CONCLUSION: The 3D bioprinting has been developed to help provide various fabrication techniques, devoting to producing structurally stable, physiologically relevant, and biologically appealing constructs. However, although the optimization of biomaterials and innovation of printing strategies may improve the fabricated vessel-like structures, 3D bioprinting is still in the infant period and has a great gap between in vitro trials and in vivo applications. The article reviews the present achievement of 3D bioprinting in generating vasculature constructs and also provides perspectives on future directions of advanced vasculature constructs fabrication.

Recent trends in natural polysaccharide based bioinks for multiscale 3D printing in tissue regeneration: A review.

Biofabrication by three-dimensional (3D) printing has been an attractive technology in harnessing the possibility to print anatomical shaped native tissues with controlled architecture and resolution. 3D printing offers the possibility to reproduce complex microarchitecture of native tissues by printing live cells in a layer by layer deposition to provide a biomimetic structural environment for tissue formation and host tissue integration. Plant based biomaterials derived from green and sustainable sources have represented to emulate native physicochemical and biological cues in order to direct specific cellular response and formation of new tissues through biomolecular recognition patterns. This comprehensive review aims to analyze and identify the most commonly used plant based bioinks for 3D printing applications. An overview on the role of different plant based biomaterial of terrestrial origin (Starch, Nanocellulose and Pectin) and marine origin (Ulvan, Alginate, Fucoidan, Agarose and Carrageenan) used for 3D printing applications are discussed elaborately. Furthermore, this review will also emphasis in the functional aspects of different 3D printers, appropriate printing material, merits and demerits of numerous plant based bioinks in developing 3D printed tissue-like constructs. Additionally, the underlying potential benefits, limitations and future perspectives of plant based bioinks for tissue engineering (TE) applications are also discussed.

Application of 3D bioprinting in the prevention and the therapy for human diseases.

Rapid development of vaccines and therapeutics is necessary to tackle the emergence of new pathogens and infectious diseases. To speed up the drug discovery process, the conventional development pipeline can be retooled by introducing advanced in vitro models as alternatives to conventional infectious disease models and by employing advanced technology for the production of medicine and cell/drug delivery systems. In this regard, layer-by-layer construction with a 3D bioprinting system or other technologies provides a beneficial method for developing highly biomimetic and reliable in vitro models for infectious disease research. In addition, the high flexibility and versatility of 3D bioprinting offer advantages in the effective production of vaccines, therapeutics, and relevant delivery systems. Herein, we discuss the potential of 3D bioprinting technologies for the control of infectious diseases. We also suggest that 3D bioprinting in infectious disease research and drug development could be a significant platform technology for the rapid and automated production of tissue/organ models and medicines in the near future.

3D Bioprinting of Human Tissues: Biofabrication, Bioinks, and Bioreactors.

The field of tissue engineering has progressed tremendously over the past few decades in its ability to fabricate functional tissue substitutes for regenerative medicine and pharmaceutical research. Conventional scaffold-based approaches are limited in their capacity to produce constructs with the functionality and complexity of native tissue. Three-dimensional (3D) bioprinting offers exciting prospects for scaffolds fabrication, as it allows precise placement of cells, biochemical factors, and biomaterials in a layer-by-layer process. Compared with traditional scaffold fabrication approaches, 3D bioprinting is better to mimic the complex microstructures of biological tissues and accurately control the distribution of cells. Here, we describe recent technological advances in bio-fabrication focusing on 3D bioprinting processes for tissue engineering from data processing to bioprinting, mainly inkjet, laser, and extrusion-based technique. We then review the associated bioink formulation for 3D bioprinting of human tissues, including biomaterials, cells, and growth factors selection. The key bioink properties for successful bioprinting of human tissue were summarized. After bioprinting, the cells are generally devoid of any exposure to fluid mechanical cues, such as fluid shear stress, tension, and compression, which are crucial for tissue development and function in health and disease. The bioreactor can serve as a simulator to aid in the development of engineering human tissues from in vitro maturation of 3D cell-laden scaffolds. We then describe some of the most common bioreactors found in the engineering of several functional tissues, such as bone, cartilage, and cardiovascular applications. In the end, we conclude with a brief insight into present limitations and future developments on the application of 3D bioprinting and bioreactor systems for engineering human tissue.

Oral Drug Delivery: Conventional to Long Acting New-Age Designs.

The Oral route of administration forms the heartwood of the ever-growing tree of drug delivery technology. It is one of the most preferred dosage forms among patients and controlled release community. Despite the high patient compliance, the deliveries of anti-cancerous drugs, vaccines, proteins, etc. via the oral route are limited and have recorded a very low bioavailability. The oral administration must overcome the physiological barriers (low solubility, permeation and early degradation) to achieve efficient and sustained delivery. This review aims at highlighting the conventional and modern-age strategies that address some of these physiological barriers. The modern age designs include the 3D printed devices and formulations. The superiority of 3D dosage forms over conventional cargos is summarized with a focus on long-acting designs. The innovations in Pharmaceutical organizations (Lyndra, Assertio and Intec) that have taken giant steps towards commercialization of long-acting vehicles are discussed. The recent advancements made in the arena of oral peptide delivery are also highlighted. The review represents a comprehensive journey from Nano-formulations to micro-fabricated oral implants aiming at specific patient-centric designs.

In Situ 3D Printing: Opportunities with Silk Inks.

In situ 3D printing is an emerging technique designed for patient-specific needs and performed directly in the patient's tissues in the operating room. While this technology has progressed rapidly, several improvements are needed to push it forward for widespread utility, including ink formulations and optimization for in situ context. Silk fibroin inks emerge as a viable option due to the diverse range of formulations, aqueous processability, robust and tunable mechanical properties, and self-assembly via biophysical adsorption to avoid exogenous chemical or photochemical sensitizer additives, among other features. In this review, we focus on this new frontier of 3D in situ printing for tissue regeneration, where silk is proposed as candidate biomaterial ink due to the unique and useful properties of this protein polymer.

Leveraging advances in chemistry to design biodegradable polymeric implants using chitosan and other biomaterials.

The metamorphosis of biodegradable polymers in biomedical applications is an auspicious myriad of indagation. The utmost challenge in clinical conditions includes trauma, organs failure, soft and hard tissues, infection, cancer and inflammation, congenital disorders which are still not medicated efficiently. To overcome this bone of contention, proliferation in the concatenation of biodegradable materials for clinical applications has emerged as a silver bullet owing to eco-friendly, nontoxicity, exorbitant mechanical properties, cost efficiency, and degradability. Several bioimplants are designed and fabricated in a way to reabsorb or degrade inside the body after performing the specific function rather than eliminating the bioimplants. The objective of this comprehensive is to unfurl the anecdote of emerging biological polymers derived implants including silk, lignin, soy, collagen, gelatin, chitosan, alginate, starch, etc. by explicating the selection, fabrication, properties, and applications. Into the bargain, emphasis on the significant characteristics of current discernment and purview of nanotechnology integrated biopolymeric implants has also been expounded. This robust contrivance shed light on recent inclinations and evolution in tissue regeneration and targeting organs followed by precedency and fly in the ointment concerning biodegradable implants evolved by employing fringe benefits provided by 3D printing technology for building tissues or organs construct for implantation.

Validación de un modelo simulado inanimado basado en impresión 3D de ureterorrenoscopía flexible / Validation of an inanimate simulated model based on flexible ureterorenoscopy 3D printing

Resumen Objetivo: Establecer validez aparente, de contenido y constructo, de un programa de simulación de ureterorrenoscopía flexible. Materiales y Método: Se desarrolló un modelo de simulación de silicona para ureterorrenoscopía flexible, en el cual se establecieron 8 marcas de colores en los distintos cálices. Para la validación, se reclutaron urólogos expertos y residentes de urología con experiencia variable en este procedimiento. Se separaron en 3 grupos: G1 para residentes sin experiencia en ureteroscopía, G2 para residentes con experiencia variable y G3 para urólogos expertos. Se les solicitó realizar una navegación completa del modelo, en un tiempo máximo de 600 segundos. Al finalizar, cada participante contestó una encuesta respecto a la utilidad y realismo del modelo. Además, se midió tiempo total, número de puntos encontrados y cantidad de veces de reingreso a los cálices para validación de constructo. Resultados: 15 personas participaron en la evaluación. Se obtuvo una mediana de 8,6 puntos para la utilidad del modelo y 6,75 puntos para el realismo de este. Los tiempos totales de navegación fueron 504, 293 y 133 segundos para G1, G2 y G3 respectivamente (p = 0,02). De las 8 marcas, se encontraron en promedio 5,1, 6,6 y 7,3 (p = 0,18), presentando un promedio de 9,5, 3,8 y 1,3 reintentos de exploración de los cálices en los respectivos grupos (p = 0,11). Conclusiones: Se establece validez aparente y contenido para un modelo de ureterorrenoscopía flexible. El programa de simulación de ureterorrenoscopía flexible establecido, permite diferenciar novatos de expertos en cuanto a reducción en los tiempos de navegación.

Aim: To establish the face, content, and construction validity of a flexible ureterorenoscopy simulation program. Materials and Method: A simulation model for flexible ureterorenoscopy was developed using silicone on which eight colored marks were marked on the calyxes. For validation, expert urologists and residents with varying amounts of experience in this procedure were recruited. They were separated into three groups: 1) G1 for residents without experience in ureteroscopy; 2) G2 for residents with variable experience; and 3) G3 for expert urologists. They were asked to perform a full navigation of the model in a maximum time of 600 sec. At the end, each participant answered a survey regarding the usefulness and realistic nature of the model. In addition, total time, number of marks found, and times of re-entry to the calyxes were measured. Results: A median of 8.6 points was obtained for the utility of the model and 6.75 points for its realistic nature. The total navigation times were 504, 293, and 133 seconds for G1, G2, and G3, respectively (p = 0.02). Of the eight marks, an average of 5.1, 6.6, and 7.3, (p = 0.18) were found with an average of 9.5, 3.8, and 1.3 exploration reattempts at the chalices in the corresponding groups (p = 0.11). Conclusions: Face and content validity was established for this simulation model of flexible ureterorenoscopy. This flexible ureterorenoscopy simulation program allowed us to differentiate the level of expertise in terms of reduction in navigation time.

3D printing promotes the development of drugs.

3D printing is an emerging field that can be found in medicine, electronics, aviation and other fields. 3D printing, with its personalized and highly customized characteristics, has great potential in the pharmaceutical industry. We were interested in how 3D printing can be used in drug fields. To find out 3D printing's application in drug fields, we collected the literature by combining the keywords "3D printing"/"additive manufacturing" and "drug"/"tablet". We found that 3D printing technology has the following applications in medicine: firstly, it can print pills on demand according to the individual condition of the patient, making the dosage more suitable for each patient's own physical condition; secondly, it can print tablets with specific shape and structure to control the release rate; thirdly, it can precisely control the distribution of cells, extracellular matrix and biomaterials to build organs or organ-on-a-chip for drug testing; finally, it could print loose porous pills to reduce swallowing difficulties, or be used to make transdermal microneedle patches to reduce pain of patients.

3D Printing Technologies: Recent Development and Emerging Applications in Various Drug Delivery Systems.

The 3D printing is considered as an emerging digitized technology that could act as a key driving factor for the future advancement and precise manufacturing of personalized dosage forms, regenerative medicine, prosthesis and implantable medical devices. Tailoring the size, shape and drug release profile from various drug delivery systems can be beneficial for special populations such as paediatrics, pregnant women and geriatrics with unique or changing medical needs. This review summarizes various types of 3D printing technologies with advantages and limitations particularly in the area of pharmaceutical research. The applications of 3D printing in tablets, films, liquids, gastroretentive, colon, transdermal and intrauterine drug delivery systems as well as medical devices have been briefed. Due to the novelty and distinct features, 3D printing has the inherent capacity to solve many formulation and drug delivery challenges, which are frequently associated with poorly aqueous soluble drugs. Recent approval of Spritam® and publication of USFDA technical guidance on additive manufacturing related to medical devices has led to an extensive research in various field of drug delivery systems and bioengineering. The 3D printing technology could be successfully implemented from pre-clinical phase to first-in-human trials as well as on-site production of customized formulation at the point of care having excellent dose flexibility. Advent of innovative 3D printing machineries with built-in flexibility and quality with the introduction of new regulatory guidelines would rapidly integrate and revolutionize conventional pharmaceutical manufacturing sector.

Patient-Specific Modeling for Structural Heart Intervention: Role of 3D Printing Today and Tomorrow CME.

Structural heart interventions (SHIs) are increasingly applicable in a wide range of heart defects, but the intricate and dynamic nature of cardiac structures can make SHIs challenging to perform. Three-dimensional (3D) printed modeling integrates advanced clinical imaging and 3D printing technology to replicate patient-specific anatomy for comprehensive planning and simulation of SHIs. This review discusses the basic principles of patient-specific 3D print model development, print material selection, and model fabrication and highlights how cardiovascular 3D printing can be used in preprocedural planning, device sizing, enhanced communication, and procedure simulation.

The Future of Skull Base Surgery: A View Through Tinted Glasses.

In the present report, we have broadly outlined the potential advances in the field of skull base surgery, which might occur within the next 20 years based on the many areas of current research in biology and technology. Many of these advances will also be broadly applicable to other areas of neurosurgery. We have grounded our predictions for future developments in an exploration of what patients and surgeons most desire as outcomes for care. We next examined the recent developments in the field and outlined several promising areas of future improvement in skull base surgery, per se, as well as identifying the new hospital support systems needed to accommodate these changes. These include, but are not limited to, advances in imaging, Raman spectroscopy and microscopy, 3-dimensional printing and rapid prototyping, master-slave and semiautonomous robots, artificial intelligence applications in all areas of medicine, telemedicine, and green technologies in hospitals. In addition, we have reviewed the therapeutic approaches using nanotechnology, genetic engineering, antitumor antibodies, and stem cell technologies to repair damage caused by traumatic injuries, tumors, and iatrogenic injuries to the brain and cranial nerves. Additionally, we have discussed the training requirements for future skull base surgeons and stressed the need for adaptability and change. However, the essential requirements for skull base surgeons will remain unchanged, including knowledge, attention to detail, technical skill, innovation, judgment, and compassion. We believe that active involvement in these rapidly evolving technologies will enable us to shape some of the future of our discipline to address the needs of both patients and our profession.