A Portable 3D Printer System for the Diagnosis and Treatment of Multidrug-Resistant Bacteria

3D Printed Materials for Combating Antimicrobial Resistance

Three-dimensional (3D) printing is a rapidly growing technology with a significant capacity for translational applications in both biology and medicine. 3D-printed living and non-living materials are being widely tested as a potential replacement for conventional solutions for testing and combating antimicrobial resistance (AMR). The precise control of cells and their microenvironment, while simulating the complexity and dynamics of an in vivo environment, provides an excellent opportunity to advance the modeling and treatment of challenging infections and other health conditions. 3D-printing models the complicated niches of microbes and host-pathogen interactions, and most importantly, how microbes develop resistance to antibiotics. In addition, 3D-printed materials can be applied to testing and delivering antibiotics. Here, we provide an overview of 3D printed materials and biosystems and their biomedical applications, focusing on ever increasing AMR. Recent applications of 3D printing to alleviate the impact of AMR, including developed bioprinted systems, targeted bacterial infections, and tested antibiotics are presented.

Electronic Structure Modulation of Ag2 S by Vacancy Engineering for Efficient Bacterial Infection

Vacancy engineering can modulate the electronic structure of the material and thus contribute to the formation of coordination unsaturated sites, which makes it easier to act on the substrate. Herein, Ag₂ S and Ag₂ S-100, which mainly have vacancy associates V_AgS and V_AgSAg , respectively, are prepared and characterized by positron annihilation spectroscopy. Both experimental and theoretical calculation results indicate that Ag₂ S-100 exhibits excellent antibacterial activity due to its appropriate bandgap and stronger bacteria-binding ability, which endow it with a superior antibacterial activity compared to Ag₂ S in the absence of light. The in vivo antibacterial experiment using a mouse wound-infection model further confirms that Ag₂ S-100 has excellent antibacterial and wound-healing properties. This research provides clues for a deeper understanding of modulating electronic structures through vacancy engineering and develops a strategy for effective treatment of bacterial infections.

From 3D printing to 3D bioprinting: the material properties of polymeric material and its derived bioink for achieving tissue specific architectures

The application of 3D printing technologies fields for biological tissues, organs, and cells in the context of medical and biotechnology applications requires a significant amount of innovation in a narrow printability range. 3D bioprinting is one such way of addressing critical design challenges in tissue engineering. In a more general sense, 3D printing has become essential in customized implant designing, faithful reproduction of microenvironmental niches, sustainable development of implants, in the capacity to address issues of effective cellular integration, and long-term stability of the cellular constructs in tissue engineering. This review covers various aspects of 3D bioprinting, describes the current state-of-the-art solutions for all aforementioned critical issues, and includes various illustrative representations of technologies supporting the development of phases of 3D bioprinting. It also demonstrates several bio-inks and their properties crucial for being used for 3D printing applications. The review focus on bringing together different examples and current trends in tissue engineering applications, including bone, cartilage, muscles, neuron, skin, esophagus, trachea, tympanic membrane, cornea, blood vessel, immune system, and tumor models utilizing 3D printing technology and to provide an outlook of the future potentials and barriers.

Automation and data-driven design of polymer therapeutics

Polymers are uniquely suited for drug delivery and biomaterial applications due to tunable structural parameters such as length, composition, architecture, and valency. To facilitate designs, researchers may explore combinatorial libraries in a high throughput fashion to correlate structure to function. However, traditional polymerization reactions including controlled living radical polymerization (CLRP) and ring-opening polymerization (ROP) require inert reaction conditions and extensive expertise to implement. With the advent of air-tolerance and automation, several polymerization techniques are now compatible with well plates and can be carried out at the benchtop, making high throughput synthesis and high throughput screening (HTS) possible. To avoid HTS pitfalls often described as "fishing expeditions," it is crucial to employ intelligent and big data approaches to maximize experimental efficiency. This is where the disruptive technologies of machine learning (ML) and artificial intelligence (AI) will likely play a role. In fact, ML and AI are already impacting small molecule drug discovery and showing signs of emerging in drug delivery. In this review, we present state-of-the-art research in drug delivery, gene delivery, antimicrobial polymers, and bioactive polymers alongside data-driven developments in drug design and organic synthesis. From this insight, important lessons are revealed for the polymer therapeutics community including the value of a closed loop design-build-test-learn workflow. This is an exciting time as researchers will gain the ability to fully explore the polymer structural landscape and establish quantitative structure-property relationships (QSPRs) with biological significance.

Leveraging open hardware to alleviate the burden of COVID-19 on global health systems

With the current rapid spread of COVID-19, global health systems are increasingly overburdened by the sheer number of people that need diagnosis, isolation and treatment. Shortcomings are evident across the board, from staffing, facilities for rapid and reliable testing to availability of hospital beds and key medical-grade equipment. The scale and breadth of the problem calls for an equally substantive response not only from frontline workers such as medical staff and scientists, but from skilled members of the public who have the time, facilities and knowledge to meaningfully contribute to a consolidated global response. Here, we summarise community-driven approaches based on Free and Open Source scientific and medical Hardware (FOSH) as well as personal protective equipment (PPE) currently being developed and deployed to support the global response for COVID-19 prevention, patient treatment and diagnostics.

Fused Deposition Modeling 3D Printing: Test Platforms for Evaluating Post-Fabrication Chemical Modifications and In-Vitro Biological Properties

3D printing is attracting considerable interest for its capacity to produce prototypes and small production runs rapidly. Fused deposit modeling (FDM) was used to produce polyvalent test plates for investigation of the physical, chemical, and in-vitro biological properties of printed materials. The polyvalent test plates (PVTPs) are poly-lactic acid cylinders, 14 mm in diameter and 3 mm in height. The polymer ester backbone was surface modified by a series of ramified and linear oligoamines to increase its hydrophilicity and introduce a positive charge. The chemical modification was verified by FT-IR spectroscopy, showing the introduction of amide and amine functions, and contact angle measurements confirmed increased hydrophilicity. Morphology studies (SEM, optical microscopy) indicated that the modification of PVTP possessed a planar morphology with small pits. Positron annihilation lifetime spectroscopy demonstrated that the polymeric free volume decreased on modification. An MTT-based prolonged cytotoxicity test using Caco-2 cells showed that the PVTPs are non-toxic at the cellular level. The presence of surface oligoamines on the PVTPs reduced biofilm formation by Candida albicans SC5314 significantly. The results demonstrate that 3D printed objects may be modified at their surface by a simple amidation reaction, resulting in a reduced propensity for biofilm colonization and cellular toxicity.

Antibiotics in 3D-printed implants, instruments and materials: benefits, challenges and future directions

3D printing is an additive manufacturing technology, which permits innovative approaches for incorporating antibiotics into 3D printed constructs. Antibiotic-incorporating applications in medicine have included medical implants, prostheses, along with procedural and surgical instruments. 3D-printed antibiotic-impregnated devices offer the advantages of increased surface area for drug distribution, sequential layers of antibiotics produced through layer-by-layer fabrication, and the ability to rapidly fabricate constructs based on patient-specific anatomies. To date, fused deposition modeling has been the main 3D printing method used to incorporate antibiotics, although inkjet and stereolithography techniques have also been described. This review offers a state-of-the-art summary of studies that incorporate antibiotics into 3D-printed constructs and summarizes the rationale, challenges, and future directions for the potential use of this technology in patient care.

Three-Dimensional Printing of Drug-Loaded Scaffolds for Antibacterial and Analgesic Applications

Pneumatic extrusion-based three-dimensional (3D) printing can be used to fabricate custom-made scaffolds to restore irregular bone defects. During the 3D printing process, therapeutic agents can be added to the scaffolds. This study aimed to develop a polycaprolactone (PCL) scaffold loaded with Ag₃PO₄ to prevent infections and lidocaine for pain relief by one-step 3D printing. We hypothesized that the drug release could be controlled by varying the filament diameter of the 3D printed scaffolds. To this end, PCL slurry mixed with different amounts of silver phosphate and lidocaine was printed via differently sized nozzles. The obtained cylindric scaffolds displayed a porous interconnected microstructure with high fidelity. The Ag₃PO₄ and lidocaine were distributed homogeneously. The lidocaine release could be controlled by adjusting the filament diameter while the silver release is correlated with the Ag₃PO₄ loading amount. The released medium from silver-loaded scaffolds exhibited an obvious inhibition zone against Staphylococcus aureus and Escherichia coli upon loading with 1% Ag₃PO₄ for up to 6 days and with 3% Ag₃PO₄ for at least 7 days. Cytotoxicity of all scaffolds was screened by cell assay. In conclusion, the pneumatic extrusion-based 3D printing provides a practical technique to fabricate drug-loaded scaffolds. The Ag₃PO₄ and lidocaine loaded PCL scaffolds showed the potential for infection prevention and pain relief.

3D printed drug delivery and testing systems - a passing fad or the future?

The US Food and Drug Administration approval of the first 3D printed tablet in 2015 has ignited growing interest in 3D printing, or additive manufacturing (AM), for drug delivery and testing systems. Beyond just a novel method for rapid prototyping, AM provides key advantages over traditional manufacturing of drug delivery and testing systems. These includes the ability to fabricate complex geometries to achieve variable drug release kinetics; ease of personalising pharmacotherapy for patient and lowering the cost for fabricating personalised dosages. Furthermore, AM allows fabrication of complex and micron-sized tissue scaffolds and models for drug testing systems that closely resemble in vivo conditions. However, there are several limitations such as regulatory concerns that may impede the progression to market. Here, we provide an overview of the advantages of AM drug delivery and testing, as compared to traditional manufacturing techniques. Also, we discuss the key challenges and future directions for AM enabled pharmaceutical applications.

3D-Printed Graphene/Polylactic Acid Electrodes Promise High Sensitivity in Electroanalysis

Additive manufacturing provides a unique tool for prototyping structures toward electrochemical sensing, due to its ability to produce highly versatile, tailored-shaped devices in a low-cost and fast way with minimized waste. Here we present 3D-printed graphene electrodes for electrochemical sensing. Ring- and disc-shaped electrodes were 3D-printed with a Fused Deposition Modeling printer and characterized using cyclic voltammetry and scanning electron microscopy. Different redox probes K₃Fe(CN)₆:K₄Fe(CN)₆, FeCl₃, ascorbic acid, Ru(NH₃)₆Cl₃, and ferrocene monocarboxylic acid) were used to assess the electrochemical performance of these devices. Finally, the electrochemical detection of picric acid and ascorbic acid was carried out as proof-of-concept analytes for sensing applications. Such customizable platforms represent promising alternatives to conventional electrodes for a wide range of sensing applications.

Point-of-care testing: applications of 3D printing

Point-of-care testing (POCT) devices fulfil a critical need in the modern healthcare ecosystem, enabling the decentralized delivery of imperative clinical strategies in both developed and developing worlds. To achieve diagnostic utility and clinical impact, POCT technologies are immensely dependent on effective translation from academic laboratories out to real-world deployment. However, the current research and development pipeline is highly bottlenecked owing to multiple restraints in material, cost, and complexity of conventionally available fabrication techniques. Recently, 3D printing technology has emerged as a revolutionary, industry-compatible method enabling cost-effective, facile, and rapid manufacturing of objects. This has allowed iterative design-build-test cycles of various things, from microfluidic chips to smartphone interfaces, that are geared towards point-of-care applications. In this review, we focus on highlighting recent works that exploit 3D printing in developing POCT devices, underscoring its utility in all analytical steps. Moreover, we also discuss key advantages of adopting 3D printing in the device development pipeline and identify promising opportunities in 3D printing technology that can benefit global health applications.