Inkjet printed antibiotic- and calcium-eluting bioresorbable nanocomposite micropatterns for orthopedic implants

The comprehensive review on 3D printing- pharmaceutical drug delivery and personalized food and nutrition

Three-dimensional printing is one of the emerging technologies that is gaining interest from the pharmaceutical industry as it provides an opportunity to customize drugs according to each patient's needs. Combining different active pharmaceutical ingredients, using different geometries, and providing sustained release enhances the effectiveness of medicine. One of the most innovative uses of 3D printing is producing fabrics, medical devices, medical implants, orthoses, and prostheses. This review summarizes the various 3D printing techniques such as stereolithography, inkjet printing, thermal inkjet printing, fused deposition modelling, extrusion printing, semi-solid extrusion printing, selective laser sintering, and hot-melt extrusion. Also, discusses the drug relies profile and its mechanisms, characteristics, and applications of the most common types of 3D printed API formulations and its recent development. Here, Authors also, summarizes the central flow of 3D food printing process and knowledge extension toward personalized nutrition.

Recent patent-based review on the role of three-dimensional printing technology in pharmaceutical and biomedical applications

Three-dimensional printing (3DP) is emerging as an innovative manufacturing technology for biomedical and pharmaceutical applications, since the US FDA approval of Spritam as a 3D-printed drug. In the present review, we have highlighted the potential benefits of 3DP technology in healthcare, such as the ability to create patient-specific medical devices and implants, as well as the possibility of on-demand production of drugs and personalized dosage forms. We have further discussed future research to optimize 3DP processes and materials for pharmaceutical and biomedical applications. Cohesively, we have put forward the current state of active patents and applications related to 3DP technology in the healthcare and pharmaceutical industries including hearing aids, prostheses, medical devices and drug-delivery systems.

PLGA-Based Nanoplatforms in Drug Delivery for Inhibition and Destruction of Microbial Biofilm

The biofilm community of microorganisms has been identified as the dominant mode of microbial growth in nature and a common characteristic of different microorganisms such as Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. The biofilm structure helps in the protection from environmental threats including host immune system and antimicrobial agents. Thus, the biofilm community has led to a higher prevalence of multidrug-resistant (MDR) strains in recent years. In this regard, the use of a new class of antibiotics, natural compounds, and anti-biofilm enzymes has been considered for the destruction of the microbial biofilm. However, different drawbacks such as low penetration, high susceptibility to degradation, instability, and poor solubility in aqueous solutions limit the use of anti-biofilm agents (ABAs) in a clinical setting. As such, recent studies have been using poly lactic-co-glycolic acid (PLGA)-based nanoplatforms (PLGA NPFs) for delivery of ABAs that have reported promising results. These particles, due to proper drug loading and release kinetics, could suppress microbial attachment, colonization, and biofilm formation for a long time. Additionally, PLGA NPFs, because of the high drug-loading efficiencies, hydrophilic surface, negative charge, and electrostatic interaction, lead to effective penetration of antibiotics to the deeper layer of the biofilm, thereby eliminating the microbial biofilm. Thus, PLGA NPFs could be considered as a potential candidate for coating catheters and other medical material surfaces for inhibition and destruction of the microbial biofilm. However, the exact interaction of PLGA NPFs and the microbial biofilm should be evaluated in animal studies. Additionally, a future goal will be to develop PLGA formulations as systems that can be used for the treatment of the MDR microbial biofilm, since the exact interactions of PLGA NPFs and these biofilm structures are not elucidated. In the present review article, we have discussed various aspects of PLGA usage for inhibition and destruction of the microbial biofilm along with different methods and procedures that have been used for improving PLGA NPF efficacy against the microbial biofilm.

The Evolution of the 3D-Printed Drug Delivery Systems: A Review

Since the appearance of the 3D printing in the 1980s it has revolutionized many research fields including the pharmaceutical industry. The main goal is to manufacture complex, personalized products in a low-cost manufacturing process on-demand. In the last few decades, 3D printing has attracted the attention of numerous research groups for the manufacturing of different drug delivery systems. Since the 2015 approval of the first 3D-printed drug product, the number of publications has multiplied. In our review, we focused on summarizing the evolution of the produced drug delivery systems in the last 20 years and especially in the last 5 years. The drug delivery systems are sub-grouped into tablets, capsules, orodispersible films, implants, transdermal delivery systems, microneedles, vaginal drug delivery systems, and micro- and nanoscale dosage forms. Our classification may provide guidance for researchers to more easily examine the publications and to find further research directions.

The Development of Innovative Dosage Forms of the Fixed-Dose Combination of Active Pharmaceutical Ingredients

The development of innovative forms of combination drugs is closely related to the invention of the multilayer tablet press, polymers for pharmaceutical applications, the hot-melt extrusion process, and 3D printing in the pharmaceutical industry. However, combining multiple drugs within the same dosage form can bring many physicochemical and pharmacodynamic interactions. More and more new forms of fixed-dose combinations (FDCs) have been developed due to work to overcome the incompatibility of active substances or to obtain different drug release profiles in the same dosage form. This review provides discussions of the application of various innovation formulation technologies of FDC drugs such as bilayer system, multilayer tablet, active film coating, hot-melt extrusion, and 3D printing, taking into account the characteristics of the key ingredients in the FDC formulation and presenting technological problems and challenges related to the development of combination drugs. Moreover, the article summarizes the range of dosage forms that have been made using these technologies over the past 30 years.

Recent advancement in 3-D printing: nanocomposites with added functionality

Three-Dimentional (3-D) printing is currently a popular printing technique that is used in many sectors. Potentially, this technology is expected to replace conventional manufacturing in the coming years. It is accelerating in gaining attention due to its design freedom where objects can be produced without imagination boundaries. The review presents a perspective on the application of 3-D printing application based on various fields. However, the ordinary 3-D printed products with a single type of raw often lack robustness leading to broken parts. Improving the mechanical property of a 3-D printed part is crucial for its applications in many fields. One of the promising solutions is to incorporate nanoparticles or fillers into the raw material. The review aims to provide information about the types of additive manufacturing. There are few types of raw materials can be used as foundation template in the printing, enhanced properties of the printed polymer nanocomposites with different types of nanoparticles as additives in the printing. The article reviews the advantages and disadvantages of different materials that are used as raw materials or base materials in 3-D printing. This can be a guideline for the readers to compare and analyse the raw materials prior to a decision on the type of material to be selected. The review prepares an overview for the researchers to choose the types of nanoparticles to be added in the printing of the products depending on the targeted application. With the added functionality of the 3-D polymer nanocomposites, it will help in widespread of the application of 3-D printing technology in various sector.

Stereolithography 3D printing technology in pharmaceuticals: a review

Three-dimensional printing (3DP) technology is an innovative tool used in manufacturing medical devices, producing alloys, replacing biological tissues, producing customized dosage forms and so on. Stereolithography (SLA), a 3D printing technique, is very rapid and highly accurate and produces finished products of uniform quality. 3D formulations have been optimized with a perfect tool of artificial intelligence learning techniques. Complex designs/shapes can be fabricated through SLA using the photopolymerization principle. Different 3DP technologies are introduced and the most promising of these, SLA, and its commercial applications, are focused on. The high speed and effectiveness of SLA are highlighted. The working principle of SLA, the materials used and applications of the technique in a wide range of different sectors are highlighted in this review. An innovative idea of 3D printing customized pharmaceutical dosage forms is also presented. SLA compromises several advantages over other methods, such as cost effectiveness, controlled integrity of materials and greater speed. The development of SLA has allowed the development of printed pharmaceutical devices. Considering the present trends, it is expected that SLA will be used along with conventional methods of manufacturing of 3D model. This 3D printing technology may be utilized as a novel tool for delivering drugs on demand. This review will be useful for researchers working on 3D printing technologies.

Recent Applications of Three Dimensional Printing in Cardiovascular Medicine

Three dimensional (3D) printing, which consists in the conversion of digital images into a 3D physical model, is a promising and versatile field that, over the last decade, has experienced a rapid development in medicine. Cardiovascular medicine, in particular, is one of the fastest growing area for medical 3D printing. In this review, we firstly describe the major steps and the most common technologies used in the 3D printing process, then we present current applications of 3D printing with relevance to the cardiovascular field. The technology is more frequently used for the creation of anatomical 3D models useful for teaching, training, and procedural planning of complex surgical cases, as well as for facilitating communication with patients and their families. However, the most attractive and novel application of 3D printing in the last years is bioprinting, which holds the great potential to solve the ever-increasing crisis of organ shortage. In this review, we then present some of the 3D bioprinting strategies used for fabricating fully functional cardiovascular tissues, including myocardium, heart tissue patches, and heart valves. The implications of 3D bioprinting in drug discovery, development, and delivery systems are also briefly discussed, in terms of in vitro cardiovascular drug toxicity. Finally, we describe some applications of 3D printing in the development and testing of cardiovascular medical devices, and the current regulatory frameworks that apply to manufacturing and commercialization of 3D printed products.

Design and Fabrication of Three-Dimensional Printed Scaffolds for Cancer Precision Medicine

Three-dimensional (3D)-engineered scaffolds have been widely investigated as drug delivery systems (DDS) or cancer models with the aim to develop effective cancer therapies. The in vitro and in vivo models developed via 3D printing (3DP) and tissue engineering concepts have significantly contributed to our understanding of cell-cell and cell-extracellular matrix interactions in the cancer microenvironment. Moreover, 3D tumor models were used to study the therapeutic efficiency of anticancer drugs. The present study aims to provide an overview of applying the 3DP and tissue engineering concepts for cancer studies with suggestions for future research directions. The 3DP technologies being used for the fabrication of personalized DDS have been highlighted and the potential technical approaches and challenges associated with the fused deposition modeling, the inkjet-powder bed, and stereolithography as the most promising 3DP techniques for drug delivery purposes are briefly described. Then, the advances, challenges, and future perspectives in tissue-engineered cancer models for precision medicine are discussed. Overall, future advances in this arena depend on the continuous integration of knowledge from cancer biology, biofabrication techniques, multiomics and patient data, and medical needs to develop effective treatments ultimately leading to improved clinical outcomes. Impact statement Three-dimensional printing (3DP) enables the fabrication of personalized medicines and drug delivery systems. The convergence of 3DP, tissue engineering concepts, and cancer biology could significantly improve our understanding of cancer biology and contribute to the development of new cancer therapies.

A 3D printed drug delivery implant formed from a dynamic supramolecular polyurethane formulation

Prototype drug eluting implants have been 3D printed using a supramolecular polyurethane-PEG formulation. The implants are capable of releasing a pharmaceutical active with effective drug release over a period of up to 8.5 months.

Three-Dimensional (3-D) Printing Technology Exploited for the Fabrication of Drug Delivery Systems

BACKGROUND

The conventional dosage forms cannot be administered to all patients because of interindividual variability found among people of different race coupled with different metabolism and cultural necessities. Therefore, to address this global issue there is a growing focus on the fabrication of new drug delivery systems customised to individual needs. Medicinal products printed using 3-D technology are transforming the current medicine business to a plausible alternative of conventional medicines.

METHODS

The PubMed database and Google scholar were browsed by keywords of 3-D printing, drug delivery, and personalised medicine. The data about techniques employed in the manufacturing of 3-D printed medicines and the application of 3-D printing technology in the fabrication of individualised medicine were collected, analysed and discussed.

RESULTS

Numerous techniques can fabricate 3-D printed medicines however, printing-based inkjet, nozzle-based deposition and laser-based writing systems are the most popular 3-D printing methods which have been employed successfully in the development of tablets, polypills, implants, solutions, nanoparticles, targeted and topical dug delivery. In addition, the approval of Spritam® containing levetiracetam by FDA as the primary 3-D printed drug product has boosted its importance. However, some drawbacks such as suitability of manufacturing techniques and the available excipients for 3-D printing need to be addressed to ensure simple, feasible, reliable and reproducible 3-D printed fabrication.

CONCLUSION

3-D printing is a revolutionary in pharmaceutical technology to cater the present and future needs of individualised medicines. Nonetheless, more investigations are required on its manufacturing aspects in terms cost effectiveness, reproducibility and bio-equivalence.

3D Printing Technology in Design of Pharmaceutical Products

Background:

Three-dimensional printing (3DP) is a novel technology for fabrication of personalized medicine. As of late, FDA affirmed 3D printed tranquilize item in August 2015, which is characteristic of another section of Pharmaceutical assembling. 3DP incorporates a wide range of assembling procedures, which are altogether founded on computer-aided design (CAD), and controlled deposition of materials (layer-by-layer) to make freestyle geometries. Conventionally, many pharmaceutical processes like compressed tablet have been used from many years for the development of tablet with established regulatory pathways. But this simple process is outdated in terms of process competence and manufacturing flexibility (design space). 3DP is a new technology for the creation of plan, proving to be superior for complex products, customized items and items made on-request. It creates new opportunities for improving efficacy, safety, and convenience of medicines.

Method:

There are many of the 3D printing technology used for the development of personalized medicine on demand for better treatment like 3D powder direct printing technology, fused-filament 3D printing, 3D extrusion printer, piezoelectric inkjet printer, fused deposition 3D printing, 3D printer, ink-jet printer, micro-drop inkjet 3DP, thermal inkjet printer, multi-nozzle 3D printer, stereolithographic 3D printer.

Result:

This review highlights features how item and process comprehension can encourage the improvement of a control technique for various 3D printing strategies.

Conclusion:

It is concluded that the 3D printing technology is a novel potential for manufacturing of personalized dose medicines, due to better patient compliance which can be prepared when needed.

An Overview of 3D Printing Technologies for Soft Materials and Potential Opportunities for Lipid-based Drug Delivery Systems

PURPOSE

Three-dimensional printing (3DP) is a rapidly growing additive manufacturing process and it is predicted that the technology will transform the production of goods across numerous fields. In the pharmaceutical sector, 3DP has been used to develop complex dosage forms of different sizes and structures, dose variations, dose combinations and release characteristics, not possible to produce using traditional manufacturing methods. However, the technology has mainly been focused on polymer-based systems and currently, limited information is available about the potential opportunities for the 3DP of soft materials such as lipids.

METHODS

This review paper emphasises the most commonly used 3DP technologies for soft materials such as inkjet printing, binder jetting, selective laser sintering (SLS), stereolithography (SLA), fused deposition modeling (FDM) and semi-solid extrusion, with the current status of these technologies for soft materials in biological, food and pharmaceutical applications.

RESULT

The advantages of 3DP, particularly in the pharmaceutical field, are highlighted and an insight is provided about the current studies for lipid-based drug delivery systems evaluating the potential of 3DP to fabricate innovative products. Additionally, the challenges of the 3DP technologies associated with technical processing, regulatory and material issues of lipids are discussed in detail.

CONCLUSION

The future utility of 3DP for printing soft materials, particularly for lipid-based drug delivery systems, offers great advantages and the technology will potentially support patient compliance and drug effectiveness via a personalised medicine approach.

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 bioprinting of tissues and organs for regenerative medicine

3D bioprinting is a pioneering technology that enables fabrication of biomimetic, multiscale, multi-cellular tissues with highly complex tissue microenvironment, intricate cytoarchitecture, structure-function hierarchy, and tissue-specific compositional and mechanical heterogeneity. Given the huge demand for organ transplantation, coupled with limited organ donors, bioprinting is a potential technology that could solve this crisis of organ shortage by fabrication of fully-functional whole organs. Though organ bioprinting is a far-fetched goal, there has been a considerable and commendable progress in the field of bioprinting that could be used as transplantable tissues in regenerative medicine. This paper presents a first-time review of 3D bioprinting in regenerative medicine, where the current status and contemporary issues of 3D bioprinting pertaining to the eleven organ systems of the human body including skeletal, muscular, nervous, lymphatic, endocrine, reproductive, integumentary, respiratory, digestive, urinary, and circulatory systems were critically reviewed. The implications of 3D bioprinting in drug discovery, development, and delivery systems are also briefly discussed, in terms of in vitro drug testing models, and personalized medicine. While there is a substantial progress in the field of bioprinting in the recent past, there is still a long way to go to fully realize the translational potential of this technology. Computational studies for study of tissue growth or tissue fusion post-printing, improving the scalability of this technology to fabricate human-scale tissues, development of hybrid systems with integration of different bioprinting modalities, formulation of new bioinks with tuneable mechanical and rheological properties, mechanobiological studies on cell-bioink interaction, 4D bioprinting with smart (stimuli-responsive) hydrogels, and addressing the ethical, social, and regulatory issues concerning bioprinting are potential futuristic focus areas that would aid in successful clinical translation of this technology.

Lactic acid of PLGA coating promotes angiogenesis on the interface between porous titanium and diabetic bone

The diabetes-related high failure risk for endosseous implants needs efficacious methods to improve osteointegration on the bone-implant interface (BII). Poly(lactic-co-glycolic) acid (PLGA) is widely used in tissue engineering but its effects on the BII in diabetes remain unclear. To clarify this issue, 3D-printed porous titanium implants (TI) with and without PLGA coating were fixed in the bone defects of sheep in vivo, and vascular endothelial cells (VEC) and osteoblasts were incubated on the implant surface under normal conditions (NC) and diabetic conditions (DC) in vitro. The results showed that the PLGA coating promoted angiogenesis on the BII and the osteointegration of TI in diabetic sheep. The PLGA coating attenuated the DC-induced dysfunctions of VEC but not of osteoblasts. When VEC and osteoblasts were co-cultured in DC, the PLGA coating showed protective effects on the osteoblasts. Lactic acid (LA) but not glycolic acid (GA), both of which are degradation products of PLGA, induced similar effects to those of PLGA. These results suggest that PLGA coating on TI could promote angiogenesis in diabetes by its degradation production of LA, thus indirectly improving the bone formation on BII. Furthermore, PLGA exerted its effects, at least partially, through inhibiting the pathological effects of advanced glycation end products (AGEs) on the BII. This is the first study of the effects of PLGA on angiogenesis on the BII and the first findings on the inhibitory effects of PLGA on AGEs. Our findings demonstrate that PLGA is a promising interface-modification component for fabricating implants with better angiogenesis and osteointegration on the BII under diabetic conditions. This strategy might be applicable for reducing implant failure in diabetic patients.

In vitro antimicrobial susceptibility testing methods: agar dilution to 3D tissue-engineered models

In the field of orthopaedic surgery, bacterial invasion of implants and the resulting periprosthetic infections are a common and unresolved problem. Antimicrobial susceptibility testing methods help to define the optimal treatment and identify antimicrobial resistance. This review discusses proven gold-standard techniques and recently developed models for antimicrobial susceptibility testing, while also providing a future outlook. Conventional, gold-standard methods, such as broth microdilution, are still widely applied in clinical settings. Although recently developed methods based on microfluidics and microdroplets have shown advantages over conventional methods in terms of testing speed, safety and the potential to provide a deeper insight into resistance mechanisms, extensive validation is required to translate this research to clinical practice. Recent optical and mechanical methods are complex and expensive and, therefore, not immediately clinically applicable. Novel osteoblast infection and tissue models best resemble infections in vivo. However, the integration of biomaterials into these models remains challenging and they require a long tissue culture, making their rapid clinical implementation unlikely. A method applicable for both clinical and research environments is difficult to realise. With a continuous increase in antimicrobial resistance, there is an urgent need for methods that analyse recurrent infections to identify the optimal treatment approaches. Graphical abstract Timeline of published and partly applied antimicrobial susceptibility testing methods, listed according to their underlying mechanism, complexity and application in research or clinics.

Inkjet deposition of itraconazole onto poly(glycolic acid) microneedle arrays

Poly(glycolic acid) microneedle arrays were fabricated using a drawing lithography process; these arrays were modified with a drug release agent and an antifungal agent by piezoelectric inkjet printing. Coatings containing poly(methyl vinyl ether-co-maleic anhydride), a water-soluble drug release layer, and itraconazole (an antifungal agent), were applied to the microneedles by piezoelectric inkjet printing. Microscopic evaluation of the microneedles indicated that the modified microneedles contained the piezoelectric inkjet printing-deposited agents and that the surface coatings were released in porcine skin. Energy dispersive x-ray spectrometry aided in confirmation that the piezoelectric inkjet printing-deposited agents were successfully applied to the desired target areas of the microneedle surface. Fourier transform infrared spectroscopy was used to confirm the presence of the component materials in the piezoelectric inkjet printing-deposited material. Itraconazole-modified microneedle arrays incubated with agar plates containing Candida albicans cultures showed zones of growth inhibition.

Biomaterials approaches to treating implant-associated osteomyelitis

Orthopaedic devices are the most common surgical devices associated with implant-related infections and Staphylococcus aureus (S. aureus) is the most common causative pathogen in chronic bone infections (osteomyelitis). Treatment of these chronic bone infections often involves combinations of antibiotics given systemically and locally to the affected site via a biomaterial spacer. The gold standard biomaterial for local antibiotic delivery against osteomyelitis, poly(methyl methacrylate) (PMMA) bone cement, bears many limitations. Such shortcomings include limited antibiotic release, incompatibility with many antimicrobial agents, and the need for follow-up surgeries to remove the non-biodegradable cement before surgical reconstruction of the lost bone. Therefore, extensive research pursuits are targeting alternative, biodegradable materials to replace PMMA in osteomyelitis applications. Herein, we provide an overview of the primary clinical treatment strategies and emerging biodegradable materials that may be employed for management of implant-related osteomyelitis. We performed a systematic review of experimental biomaterials systems that have been evaluated for treating established S. aureus osteomyelitis in an animal model. Many experimental biomaterials were not decisively more efficacious for infection management than PMMA when delivering the same antibiotic. However, alternative biomaterials have reduced the number of follow-up surgeries, enhanced the antimicrobial efficacy by delivering agents that are incompatible with PMMA, and regenerated bone in an infected defect. Understanding the advantages, limitations, and potential for clinical translation of each biomaterial, along with the conditions under which it was evaluated (e.g. animal model), is critical for surgeons and researchers to navigate the plethora of options for local antibiotic delivery.

3D printed bioceramics for dual antibiotic delivery to treat implant-associated bone infection

Surgical implant-associated bone infections (osteomyelitis) have severe clinical and socioeconomic consequences. Treatment of chronic bone infections often involves antibiotics given systemically and locally to the affected site in poly (methyl methacrylate) (PMMA) bone cement. Given the high antibiotic concentrations required to affect bacteria in biofilm, local delivery is important to achieve high doses at the infection site. PMMA is not suitable to locally-deliver some biofilm-specific antibiotics, including rifampin, due to interference with PMMA polymerisation. To examine the efficacy of localised, combinational antibiotic delivery compared to PMMA standards, we fabricated rifampin- and vancomycin-laden calcium phosphate scaffolds (CPS) by three-dimensional (3D) printing to treat an implant-associated Staphylococcus aureus bone infection in a murine model. All vancomycin- and rifampin-laden CPS treatments significantly reduced the bacterial burden compared with vancomycin-laden PMMA. The bones were bacteria culture negative in 50 % of the mice that received sustained release vancomycin- and rifampin-laden CPS. In contrast, 100 % of the bones treated with vancomycin monotherapy using PMMA or CPS were culture positive. Yet, the monotherapy CPS significantly reduced the bacterial metabolic load following revision compared to PMMA. Biofilm persisted on the fixation hardware, but the infection-induced bone destruction was significantly reduced by local rifampin delivery. These data demonstrate that, despite the challenging implant-retaining infection model, co-delivery of rifampin and vancomycin from 3D printed CPS, which is not possible with PMMA, significantly improved the outcomes of implant-associated osteomyelitis. However, biofilm persistence on the fixation hardware reaffirms the importance of implant exchange or other biofilm eradication strategies to complement local antibiotics.

A flexible-dose dispenser for immediate and extended release 3D printed tablets

The advances in personalised medicine increased the demand for a fast, accurate and reliable production method of tablets that can be digitally controlled by healthcare staff. A flexible dose tablet system is presented in this study that proved to be suitable for immediate and extended release tablets with a realistic drug loading and an easy-to-swallow tablet design. The method bridges the affordable and digitally controlled Fused Deposition Modelling (FDM) 3D printing with a standard pharmaceutical manufacturing process, Hot Melt Extrusion (HME). The reported method was compatible with three methacrylic polymers (Eudragit RL, RS and E) as well as a cellulose-based one (hydroxypropyl cellulose, HPC SSL). The use of a HME based pharmaceutical filament preserved the linear relationship between the mass and printed volume and was utilized to digitally control the dose via an input from computer software with dose accuracy in the range of 91-95%. Higher resolution printing quality doubled the printing time, but showed a little effect on in vitro release pattern of theophylline and weight accuracy. Physical characterization studies indicated that the majority of the model drug (theophylline) in the 3D printed tablet exists in a crystal form. Owing to the small size, ease of use and the highly adjustable nature of FDM 3D printers, the method holds promise for future individualised treatment.

Inkjet Printing of Regenerated Silk Fibroin: From Printable Forms to Printable Functions

A formulation of regenerated silk fibroin solution that can be easily functionalized and inkjet printed on numerous surfaces is developed. As an example, the inks can be printed on laboratory gloves that change color when exposed to bacteria.

Microbeads-Guided Reconstruction of 3D Osteocyte Network during Microfluidic Perfusion Culture

Osteocytes reside as 3-dimensionally networked cells in the lacunocanalicular structure of bones, and function as the master regulators of homeostatic bone remodeling. We report here, for the first time to our best knowledge, the use of a biomimetic approach to reconstruct the 3D osteocyte network with physiological relevant microscale dimensions. In this approach, biphasic calcium phosphate microbeads were assembled with murine early osteocytes (MLO-A5) to provide an initial mechanical framework for 3D network formation and maintenance during long-term perfusion culture in a microfluidic chamber. The microbead size of 20-25 μm was used to: (1) facilitate a single cell to be placed within the interstitial space between the microbeads, (2) mitigate the proliferation of the entrapped cell due to its physical confinement in the interstitial site, and (3) control cell-to-cell distance to be 20-25 μm as observed in murine bones. The entrapped cells formed a 3D cellular network by extending and connecting their processes through openings between the microbeads within 3 days of culture. The entrapped cells produced significant mineralized extracellular matrix to fill up the interstitial spaces, resulting in the formation of a dense tissue structure during the course of 3-week culture. We found that the time-dependent osteocytic transitions of the cells exhibited trends consistent with in vivo observations, particularly with high expression of Sost gene, which is a key osteocyte-specific marker for the mechanotransduction function of osteocytes. In contrast, cells cultured in 2D well-plates did not replicate in vivo trends. These results provide an important new insight in building physiologically relevant in vitro bone tissue models.

Inkjet printing for pharmaceutics - A review of research and manufacturing

Global regulatory, manufacturing and consumer trends are driving a need for change in current pharmaceutical sector business models, with a specific focus on the inherently expensive research costs, high-risk capital-intensive scale-up and the traditional centralised batch manufacturing paradigm. New technologies, such as inkjet printing, are being explored to radically transform pharmaceutical production processing and the end-to-end supply chain. This review provides a brief summary of inkjet printing technologies and their current applications in manufacturing before examining the business context driving the exploration of inkjet printing in the pharmaceutical sector. We then examine the trends reported in the literature for pharmaceutical printing, followed by the scientific considerations and challenges facing the adoption of this technology. We demonstrate that research activities are highly diverse, targeting a broad range of pharmaceutical types and printing systems. To mitigate this complexity we show that by categorising findings in terms of targeted business models and Active Pharmaceutical Ingredient (API) chemistry we have a more coherent approach to comparing research findings and can drive efficient translation of a chosen drug to inkjet manufacturing.

Does translational symmetry matter on the micro scale? Fibroblastic and osteoblastic interactions with the topographically distinct poly(ε-caprolactone)/hydroxyapatite thin films

Material composition and topography of the cell-contacting material interface are important considerations in the design of biomaterials at the nano and micro scales. This study is one of the first to have assessed the osteoblastic response to micropatterned polymer-ceramic composite surfaces. In particular, the effect of topographic variations of composite poly(ε-caprolactone)/hydroxyapatite (PCL/HAp) films on viability, proliferation, migration and osteogenesis of fibroblastic and osteoblastic MC3T3-E1 cells was evaluated. To that end, three different micropatterned PCL/HAp films were compared: flat and textured, the latter of which included films comprising periodically arranged and randomly distributed oval topographic features 10 μm in diameter, 20 μm in separation and 10 μm in height, comparable to the dimensions of MC3T3-E1 cells. PCL/HAp films were fabricated by the combination of a bottom-up, soft chemical synthesis of the ceramic, nanoparticulate phase and a top-down, photolithographic technique for imprinting fine, microscale features on them. X-ray diffraction analysis indicated an isotropic orientation of both the polymeric chains and HAp crystallites in the composite samples. Biocompatibility tests indicated no significant decrease in their viability when grown on PCL/HAp films. Fibroblast proliferation and migration onto PCL/HAp films proceeded slower than on the control borosilicate glass, with the flat composite film fostering more cell migration activity than the films containing topographic features. The gene expression of seven analyzed osteogenic markers, including procollagen type I, osteocalcin, osteopontin, alkaline phosphatase, and the transcription factors Runx2 and TGFβ-1, was, however, consistently upregulated in cells grown on PCL/HAp films comprising periodically ordered topographic features, suggesting that the higher levels of symmetry of the topographic ordering impose a moderate mechanochemical stress on the adherent cells and thus promote a more favorable osteogenic response. The obtained results suggest that topography can be a more important determinant of the cell/surface interaction than the surface chemistry and/or stiffness as well as that the regularity of the distribution of topographic features can be a more important variable than the topographic features per se.

Towards fabrication of 3D printed medical devices to prevent biofilm formation

The use of three-dimensional (3D) printing technologies is transforming the way that materials are turned into functional devices. We demonstrate in the current study the incorporation of anti-microbial nitrofurantoin in a polymer carrier material and subsequent 3D printing of a model structure, which resulted in an inhibition of biofilm colonization. The approach taken is very promising and can open up new avenues to manufacture functional medical devices in the future.

Organic nanocomposite structure tailored by controlling droplet coalescence during inkjet printing

Inkjet printing offers a low-cost, high-throughput avenue for producing functional organic materials through rapid translation of desktop discoveries to industrial roll-to-roll processes. Here, we report a simple, but effective strategy to control droplet coalescence during inkjet printing, as a major variable, to tailor the nanoscale morphology of organic composite materials produced upon evaporation of all-liquid inks. During deposition, the spacing between ink droplets was controlled to systematically vary the extent of droplet coalescence. Our results show that decreasing coalescence increased the solvent evaporation rate, supersaturation of the solutes, and nucleation density of the precipitating organic crystals. This phenomenon was utilized to tailor the average size of pentaerythritol tetranitrate (PETN) crystals dispersed in an adhesive binder matrix from ~0.2 to upwards of 100 μm. The results suggest that controlling the extent of droplet coalescence can be used as an effective means to tailor the composite morphology of printed organic materials at the nanoscale.