On-chip synthesis of fine-tuned bone-seeking hybrid nanoparticles

Microfluidic Synthesis of Magnetic Nanoparticles for Biomedical Applications

Magnetic nanoparticles have attracted great attention and become promising candidates in the biomedicine field due to their special physicochemical properties. They are generally divided into metallic and non-metallic magnetic nanoparticles, according to their compositions. Both of the two types have shown practical values in biomedicine applications, such as drug delivery, biosensing, bioimaging, and so on. Research efforts are devoted to the improvement of synthesis strategies to achieve magnetic nanoparticles with controllable morphology, diverse composition, active surface, or multiple functions. Taking high repeatability, programmable operation, precise fluid control, and simple device into account, the microfluidics system can expand the production scale and develop magnetic nanoparticles with desired features. This review will first describe different classifications of promising magnetic nanoparticles, followed by the advancements in microfluidic synthesis and the latest biomedical applications of these magnetic nanoparticles. In addition, the challenges and prospects of magnetic nanoparticles in the biomedical field are also discussed.

Harnessing Biomaterials to Amplify Immunity in Aged Mice through T Memory Stem Cells

The durability of a protective immune response generated by a vaccine depends on its ability to induce long-term T cell immunity, which tends to decline in aging populations. The longest protection appears to arise from T memory stem cells (TMSCs) that confer high expandability and effector functions when challenged. Here we engineered artificial antigen presenting cells (aAPC) with optimized size, stiffness and activation signals to induce human and mouse CD8+ TMSCs in vitro. This platform was optimized as a vaccine booster of TMSCs (Vax-T) with prolonged release of small-molecule blockade of the glycogen synthase kinase-3β together with target antigens. By using SARS-CoV-2 antigen as a model, we show that a single injection of Vax-T induces durable antigen-specific CD8+ TMSCs in young and aged mice, and generates humoral responses at a level stronger than or similar to soluble vaccines. This Vax-T approach can boost long-term immunity to fight infectious diseases, cancer, and other diseases.

Effect of antibacterial photodynamic therapy with chitosan nanoparticles on Aggregatibacter actinomycetemcomitans

BACKGROUND

This study aimed to assess the effect of antibacterial photodynamic therapy (aPDT) with chitosan nanoparticles on Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in the culture medium.

MATERIALS AND METHODS

In this in vitro, experimental study, chitosan nanoparticles (CHNPs) containing indocyanine green (ICG) were first synthesized and characterized. A. actinomycetemcomitans was cultured on trypticase soy agar. The culture media containing A. actinomycetemcomitans were randomly subjected to the following six decontamination protocols: negative control subjected to sterile phosphate buffered saline (PBS) for 5 min, positive control exposed to 0.2 % chlorhexidine (CHX) for 5 min, exposure to 0.25 mg/mL ICG in the dark at 37 °C for 5 min, aPDT with 0.25 mg/mL ICG and diode laser (808 nm, 250 mW, 14.94 J/cm2, 30 s, 1 mm distance, 8 mm tip diameter), exposure to CHNPs containing 0.25 mg/mL ICG in the dark at 37 °C for 5 min, and aPDT with CHNPs containing 0.25 mg/mL ICG and diode laser. The number of colonies was counted, and analyzed by one-way ANOVA and Tamhane test (alpha=0.050).

RESULTS

Antimicrobial PDT with CHNPs, and CHX groups comparably showed the highest decontamination efficacy (P = 0.000).

CONCLUSION

The results showed optimal efficacy of aPDT with CHNPs containing 0.25 mg/mL ICG and 808 nm diode laser for reduction of A. actinomycetemcomitans colony count. Thus, aPDT appears to be as effective as CHX, but with fewer adverse effects.

Synthesis and Characterization of Hydrogel Droplets Containing Magnetic Nano Particles, in a Microfluidic Flow-Focusing Chip

Magnetic hybrid hydrogels have exhibited remarkable efficacy in various areas, particularly in the biomedical sciences, where these inventive substances exhibit intriguing prospects for controlled drug delivery, tissue engineering, magnetic separation, MRI contrast agents, hyperthermia, and thermal ablation. Additionally, droplet-based microfluidic technology enables the fabrication of microgels possessing monodisperse characteristics and controlled morphological shapes. Here, alginate microgels containing citrated magnetic nanoparticles (MNPs) were produced by a microfluidic flow-focusing system. Superparamagnetic magnetite nanoparticles with an average size of 29.1 ± 2.5 nm and saturation magnetization of 66.92 emu/g were synthesized via the co-precipitation method. The hydrodynamic size of MNPs was changed from 142 nm to 826.7 nm after the citrate group's attachment led to an increase in dispersion and the stability of the aqueous phase. A microfluidic flow-focusing chip was designed, and the mold was 3D printed by stereo lithographic technology. Depending on inlet fluid rates, monodisperse and polydisperse microgels in the range of 20-120 μm were produced. Different conditions of droplet generation in the microfluidic device (break-up) were discussed considering the model of rate-of-flow-controlled-breakup (squeezing). Practically, this study indicates guidelines for generating droplets with a predetermined size and polydispersity from liquids with well-defined macroscopic properties, utilizing a microfluidic flow-focusing device (MFFD). Fourier transform infrared spectrometer (FT-IR) results indicated a chemical attachment of citrate groups on MNPs and the existence of MNPs in the hydrogels. Magnetic hydrogel proliferation assay after 72 h showed a better rate of cell growth in comparison to the control group (p = 0.042).

Nanoparticles in the diagnosis and treatment of cancer metastases: Current and future perspectives

Metastasis accounts for greater than 90% of cancer-related deaths. Despite recent advancements in conventional chemotherapy, immunotherapy, targeted therapy, and their rational combinations, metastatic cancers remain essentially untreatable. The distinct obstacles to treat metastases include their small size, high multiplicity, redundancy, therapeutic resistance, and dissemination to multiple organs. Recent advancements in nanotechnology provide the numerous applications in the diagnosis and prophylaxis of metastatic diseases, including the small particle size to penetrate cell membrane and blood vessels and their capacity to transport complex molecular 'cargo' particles to various metastatic regions such as bones, brain, liver, lungs, and lymph nodes. Indeed, nanoparticles (NPs) have demonstrated a significant ability to target specific cells within these organs. In this regard, the purpose of this review is to summarize the present state of nanotechnology in terms of its application in the diagnosis and treatment of metastatic cancer. We intensively reviewed applications of NPs in fluorescent imaging, PET scanning, MRI, and photoacoustic imaging to detect metastasis in various cancer models. The use of targeted NPs for cancer ablation in conjunction with chemotherapy, photothermal treatment, immuno therapy, and combination therapy is thoroughly discussed. The current review also highlights the research opportunities and challenges of leveraging engineering technologies with cancer cell biology and pharmacology to fabricate nanoscience-based tools for treating metastases.

Systemic enhancement of antitumour immunity by peritumourally implanted immunomodulatory macroporous scaffolds

A tumour microenvironment abundant in regulatory T (Treg) cells aids solid tumours to evade clearance by effector T cells. Systemic strategies to suppress Treg cells or to augment immunity can elicit autoimmune side effects, cytokine storms and other toxicities. Here we report the design, fabrication and therapeutic performance of a biodegradable macroporous scaffold, implanted peritumourally, that releases a small-molecule inhibitor of transforming growth factor β to suppress Treg cells, chemokines to attract effector T cells and antibodies to stimulate them. In two mouse models of aggressive tumours, the implant boosted the recruitment and activation of effector T cells into the tumour and depleted it of Treg cells, which resulted in an 'immunological abscopal effect' on distant metastases and in the establishment of long-term memory that impeded tumour recurrence. We also show that the scaffold can be used to deliver tumour-antigen-specific T cells into the tumour. Peritumourally implanted immunomodulatory scaffolds may represent a general strategy to enhance T-cell immunity and avoid the toxicities of systemic therapies.

PLGA-based nanoparticles for the treatment of cancer: current strategies and perspectives

Research on cancer treatment is always of great importance because of the extensive and difficult treatment options and side effects of chemotherapeutic agents. Due to this, novel techniques for cancer treatment are the need of the day. Nowadays, nanotechnology is of great interest for its applications as diagnostic tools, theragnostic, contrasting agents, and vehicles for delivering drugs. Nanoparticles (NPs) are made up of biocompatible and biodegradable polymers that improve the pharmacokinetic and pharmacodynamic properties of drugs, reduce side effects, improve stability, prolong the release of drug, and reduce the dosing frequency. Poly (lactic-co-glycolic acid) (PLGA) is FDA-approved synthetic polymer which can be used to formulate NPs that can be targeted to a specific site for the safe and effective delivery of drugs. PLGA-based NPs can be used for a variety of cancer therapies including tumor-targeted drug delivery, gene therapy, hyperthermia, and photodynamic therapy. This article discusses the method of preparation, characterization, encapsulation of chemotherapeutic drugs, effect of physicochemical properties of PLGA- based NPs, and how we can exploit these aspects through various methods of preparation for drug loading, biodistribution, target specificity, and their use in cancer treatment. Along with these targeting strategies, gene therapy, cancer immunotherapy, and various applications have also been discussed. This article also aims to discuss the incorporation of diagnostic tools and therapeutic moiety in one versatile formulation of PLGA-NPs and the difficulties faced in translating this promising tool to clinical use.

Microfluidic Nanoparticles for Drug Delivery

Nanoparticles (NPs) have attracted tremendous interest in drug delivery in the past decades. Microfluidics offers a promising strategy for making NPs for drug delivery due to its capability in precisely controlling NP properties. The recent success of mRNA vaccines using microfluidics represents a big milestone for microfluidic NPs for pharmaceutical applications, and its rapid scaling up demonstrates the feasibility of using microfluidics for industrial-scale manufacturing. This article provides a critical review of recent progress in microfluidic NPs for drug delivery. First, the synthesis of organic NPs using microfluidics focusing on typical microfluidic methods and their applications in making popular and clinically relevant NPs, such as liposomes, lipid NPs, and polymer NPs, as well as their synthesis mechanisms are summarized. Then, the microfluidic synthesis of several representative inorganic NPs (e.g., silica, metal, metal oxide, and quantum dots), and hybrid NPs is discussed. Lastly, the applications of microfluidic NPs for various drug delivery applications are presented.

Microfluidic Roadmap for Translational Nanotheranostics

Nanotheranostic materials (NTMs) shed light on the mechanisms responsible for complex diseases such as cancer because they enable making a diagnosis, monitoring the disease progression, and applying a targeted therapy simultaneously. However, several issues such as the reproducibility and mass production of NTMs hamper their application for clinical practice. To address these issues and facilitate the clinical application of NTMs, microfluidic systems have been increasingly used. This perspective provides a glimpse into the current state-of-art of NTM research, emphasizing the methods currently employed at each development stage of NTMs and the related open problems. This work reviews microfluidic technologies used to develop NTMs, ranging from the fabrication and testing of a single NTM up to their manufacturing on a large scale. Ultimately, a step-by-step vision on the future development of NTMs for clinical practice enabled by microfluidics techniques is provided.

Towards principled design of cancer nanomedicine to accelerate clinical translation

Nanotechnology in medical applications, especially in oncology as drug delivery systems, has recently shown promising results. However, although these advances have been promising in the pre-clinical stages, the clinical translation of this technology is challenging. To create drug delivery systems with increased treatment efficacy for clinical translation, the physicochemical characteristics of nanoparticles such as size, shape, elasticity (flexibility/rigidity), surface chemistry, and surface charge can be specified to optimize efficiency for a given application. Consequently, interdisciplinary researchers have focused on producing biocompatible materials, production technologies, or new formulations for efficient loading, and high stability. The effects of design parameters can be studied in vitro, in vivo, or using computational models, with the goal of understanding how they affect nanoparticle biophysics and their interactions with cells. The present review summarizes the advances and technologies in the production and design of cancer nanomedicines to achieve clinical translation and commercialization. We also highlight existing challenges and opportunities in the field.

Biomaterials for Orthopaedic Diagnostics and Theranostics

Despite widespread use of conventional diagnostic methods in orthopaedic applications, limitations still exist in detection and diagnosing many pathologies especially at early stages when intervention is most critical. The use of biomaterials to develop diagnostics and theranostics, including nanoparticles and scaffolds for systemic or local applications, has significant promise to address these shortcomings and enable successful clinical translation. These developments in both modular and holistic design of diagnostic and theranostic biomaterials may improve patient treatments for myriad orthopaedic applications ranging from cancer to fractures to infection.

Microfluidic Synthesis, Control, and Sensing of Magnetic Nanoparticles: A Review

Magnetic nanoparticles have attracted significant attention in various disciplines, including engineering and medicine. Microfluidic chips and lab-on-a-chip devices, with precise control over small volumes of fluids and tiny particles, are appropriate tools for the synthesis, manipulation, and evaluation of nanoparticles. Moreover, the controllability and automation offered by the microfluidic chips in combination with the unique capabilities of the magnetic nanoparticles and their ability to be remotely controlled and detected, have recently provided tremendous advances in biotechnology. In particular, microfluidic chips with magnetic nanoparticles serve as sensitive, high throughput, and portable devices for contactless detecting and manipulating DNAs, RNAs, living cells, and viruses. In this work, we review recent fundamental advances in the field with a focus on biomedical applications. First, we study novel microfluidic-based methods in synthesizing magnetic nanoparticles as well as microparticles encapsulating them. We review both continues-flow and droplet-based microreactors, including the ones based on the cross-flow, co-flow, and flow-focusing methods. Then, we investigate the microfluidic-based methods for manipulating tiny magnetic particles. These manipulation techniques include the ones based on external magnets, embedded micro-coils, and magnetic thin films. Finally, we review techniques invented for the detection and magnetic measurement of magnetic nanoparticles and magnetically labeled bioparticles. We include the advances in anisotropic magnetoresistive, giant magnetoresistive, tunneling magnetoresistive, and magnetorelaxometry sensors. Overall, this review covers a wide range of the field uniquely and provides essential information for designing "lab-on-a-chip" systems for synthesizing magnetic nanoparticles, labeling bioparticles with them, and sorting and detecting them on a single chip.

Drug Delivery to the Bone Microenvironment Mediated by Exosomes: An Axiom or Enigma

The increasing incidence of bone-related disorders is causing a burden on the clinical scenario. Even though bone is one of the tissues that possess tremendous regenerative potential, certain bone anomalies need therapeutic intervention through appropriate delivery of a drug. Among several nanosystems and biologics that offer the potential to contribute towards bone healing, the exosomes from the class of extracellular vesicles are outstanding. Exosomes are extracellular nanovesicles that, apart from the various advantages, are standing out of the crowd for their ability to conduct cellular communication. The internal cargo of the exosomes is leading to its potential use in therapeutics. Exosomes are being unraveled in terms of the mechanism as well as application in targeting various diseases and tissues. Through this review, we have tried to understand and review all that is already established and the gap areas that still exist in utilizing them as drug delivery vehicles targeting the bone. The review highlights the potential of the exosomes towards their contribution to the drug delivery scenario in the bone microenvironment. A comparison of the pros and cons of exosomes with other prevalent drug delivery systems is also done. A section on the patents that have been generated so far from this field is included.

Biomaterial-based immunoengineering to fight COVID-19 and infectious diseases

Infection by SARS-CoV-2 virus often induces the dysregulation of immune responses, tissue damage, and blood clotting. Engineered biomaterials from the nano- to the macroscale can provide targeted drug delivery, controlled drug release, local immunomodulation, enhanced immunity, and other desirable functions to coordinate appropriate immune responses and to repair tissues. Based on the understanding of COVID-19 disease progression and immune responses to SARS-CoV-2, we discuss possible immunotherapeutic strategies and highlight biomaterial approaches from the perspectives of preventive immunization, therapeutic immunomodulation, and tissue healing and regeneration. Successful development of biomaterial platforms for immunization and immunomodulation will not only benefit COVID-19 patients, but also have broad applications for a variety of infectious diseases.

Interventional Techniques for Bone and Musculoskeletal Soft Tissue Tumors: Current Practices and Future Directions - Part II. Stabilization

Percutaneous image-guided oncologic interventions have rapidly evolved over the last two decades as an independent strategy or used within a first-, second-, or even third-line strategy in the treatment of musculoskeletal (MSK) tumors. Abundant mostly nonrandomized publications have described the safety, efficacy, and reproducibility of implementing percutaneous therapies both with curative and palliative intent. In this article, we continue to share our experience in bone and MSK soft tissue interventions focusing on stabilization and combined ablation and stabilization. We propose a pathway and explore future directions of image-guided interventional oncology related to skeletal disease. We reflect on the advantages and limitations of each technique and offer guidance and pearls to improve outcomes. Representing patterns from our practices, we demonstrate the role of collaborative working within a multidisciplinary team, ideally within a dedicated tumor treatment center, to deliver patient-specific therapy plans that are value based and favored by patients when given the choice.

Targeting nanoparticles for diagnosis and therapy of bone tumors: Opportunities and challenges

A variety of targeted nanoparticles were developed for the diagnosis and therapy of orthotopic and metastatic bone tumors during the past decade. This critical review will focus on principles and methods in the design of these bone-targeted nanoparticles. Ligands including bisphosphonates, aspartic acid-rich peptides and synthetic polymers were grafted on nanoparticles such as PLGA nanoparticles, liposomes, dendrimers and inorganic nanoparticles for bone targeting. Besides, other ligands such as monoclonal antibodies, peptides and aptamers targeting biomarkers on tumor/bone cells were identified for targeted diagnosis and therapy. Examples of targeted nanoparticles for the early detection of bone metastatic tumors and the ablation of cancer via chemotherapy, photothermal therapy, gene therapy and combination therapy will be intensively reviewed. The development of multifunctional nanoparticles to break down the "vicious" cycle between tumor cell proliferation and bone resorption, and the challenges and perspectives in this area will be discussed.

Microfluidic-mediated nano-drug delivery systems: from fundamentals to fabrication for advanced therapeutic applications

Nano-drug delivery systems (NDDS) are functional drug-loaded nanocarriers extensively applied in the healthcare and pharmaceutical areas. Recently, microfluidics has been demonstrated as one of the most promising techniques to fabricate high-performance NDDS with uniform morphology, size and size distribution, reduced batch-to-batch variations and controllable drug delivering capacity. Here, a brief review of the microfluidic-mediated NDDS is presented. The fundamentals of microfluidics are first interpreted with an emphasis on the fluid characteristics, design and materials for microfluidic devices. Then a comprehensive and in-depth depiction of the microfluidic-mediated fabrications of controllable NDDS with well-tailored internal structures and integrated functions for controlled encapsulation and drug release are categorized and reviewed, with particular descriptions about the underlying formation mechanisms. Afterwards, recently appreciated representative applications of the microfluidic-mediated NDDS for delivering multiple drugs are systematically summarized. Finally, conclusions and perspectives on further advancing the microfluidic-mediated NDDS toward more powerful and versatile platforms for therapeutic applications are discussed.

Synthesis and Surface Engineering of Inorganic Nanomaterials Based on Microfluidic Technology

The controlled synthesis and surface engineering of inorganic nanomaterials hold great promise for the design of functional nanoparticles for a variety of applications, such as drug delivery, bioimaging, biosensing, and catalysis. However, owing to the inadequate and unstable mass/heat transfer, conventional bulk synthesis methods often result in the poor uniformity of nanoparticles, in terms of microstructure, morphology, and physicochemical properties. Microfluidic technologies with advantageous features, such as precise fluid control and rapid microscale mixing, have gathered the widespread attention of the research community for the fabrication and engineering of nanomaterials, which effectively overcome the aforementioned shortcomings of conventional bench methods. This review summarizes the latest research progress in the microfluidic fabrication of different types of inorganic nanomaterials, including silica, metal, metal oxides, metal organic frameworks, and quantum dots. In addition, the surface modification strategies of nonporous and porous inorganic nanoparticles based on microfluidic method are also introduced. We also provide the readers with an insight on the red blocks and prospects of microfluidic approaches, for designing the next generation of inorganic nanomaterials.

Microfluidic fabrication and characterization of Sorafenib-loaded lipid-polymer hybrid nanoparticles for controlled drug delivery

Lipid polymer hybrid nanoparticles (LPHNPs) have been merged as potential nanocarriers for treatment of cancer. In the present study, LPHNPs loaded with Sorafenib (SFN) were prepared with PLGA, Lecithin and DSPE-PEG 2000 by using the bulk nanoprecipitation and microfluidic (MF) co-flow nanoprecipitation techniques. Herein, a glass capillary microfluidic device was primed to optimize the LPHNPs and compared to the bulk nanoprecipitation method. The morphological analysis of prepared LPHNPs revealed the well-defined spherical nano-sized particles in bulk nanoprecipitation method. Whereas, core shell morphology was observed in the MF method. The formulation prepared by the MF method (MF1-MF3) indicated relatively higher % EE (95.0%, 93.8% and 88.7%) and controlled release of the SFN from the particles as compared to the LPHNPs obtained by the bulk nanoprecipitation method. However, the release of SFN from all LPHNP formulation followed Higuchi model (R² = 0.9901-0.9389) with Fickian diffusion mechanism. Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and powder X-rays diffraction (pXRD) studies depicted the compatibility of SFN with all the structural components. In addition, the colloidal stability, in vitro cytotoxicity and cell growth inhibition studies of LPHNPs also demonstrated stability in biological media, biocompatibility and safety with enhanced anti-proliferative effects than the free SFN in breast cancer and prostate cancer cells. In conclusion, LPHNPs provided a prospective platform for the cancer chemotherapy and substantially improved the knowledge of fabrication and optimization of the hybrid nanoparticles.

The Application of Microfluidic Techniques on Tissue Engineering in Orthopaedics

Background:

Tissue engineering (TE) is a promising solution for orthopaedic diseases such as bone or cartilage defects and bone metastasis. Cell culture in vitro and scaffold fabrication are two main parts of TE, but these two methods both have their own limitations. The static cell culture medium is unable to achieve multiple cell incubation or offer an optimal microenvironment for cells, while regularly arranged structures are unavailable in traditional cell-laden scaffolds, which results in low biocompatibility. To solve these problems, microfluidic techniques are combined with TE. By providing 3-D networks and interstitial fluid flows, microfluidic platforms manage to maintain phenotype and viability of osteocytic or chondrocytic cells, and the precise manipulation of liquid, gel and air flows in microfluidic devices leads to the highly organized construction of scaffolds.

Methods:

In this review, we focus on the recent advances of microfluidic techniques applied in the field of tissue engineering, especially in orthropaedics. An extensive literature search was done using PubMed. The introduction describes the properties of microfluidics and how it exploits the advantages to the full in the aspects of TE. Then we discuss the application of microfluidics on the cultivation of osteocytic cells and chondrocytes, and other extended researches carried out on this platform. The following section focuses on the fabrication of highly organized scaffolds and other biomaterials produced by microfluidic devices. Finally, the incubation and studying of bone metastasis models in microfluidic platforms are discussed.

Conclusion:

The combination of microfluidics and tissue engineering shows great potentials in the osteocytic cell culture and scaffold fabrication. Though there are several problems that still require further exploration, the future of microfluidics in TE is promising.

Microfluidic assisted synthesis of PLGA drug delivery systems

Poly(lactic-co-glycolic acid) (PLGA) is a biocompatible and biodegradable polymer that recently attracted attention for use as part of drug delivery systems (DDS). In this context, there is an emerging need for a rapid, reliable and reproducible method of synthesis. Here, microfluidic systems provide great opportunities for synthesizing carriers in a tightly controlled manner and with low consumption of materials, energy and time. These miniature devices have been the focus of recent research since they can address the challenges inherent to the bulk system, e.g. low drug loading efficiency and encapsulation, broad size distribution and burst initial release. In this article, we provide an overview of current microfluidic systems used in drug delivery production, with a special focus on PLGA-based DDS. In this context, we highlight the advantages associated with the use of microchip systems in the fabrication of nanoparticles (NPs) and microparticles (MPs), e.g. in achieving complex morphologies. Furthermore, we discuss the challenges for selecting proper microfluidics for targeted DDS production in a translational setting and introduce strategies that are used to overcome microfluidics shortcomings, like low throughput for production.

Poly(lactic-co-glycolic acid) (PLGA) is a biocompatible and biodegradable polymer that recently attracted attention for use as part of drug delivery systems (DDS).

PLGA-Based Nanoparticles in Cancer Treatment

Nanomedicines can be used for a variety of cancer therapies including tumor-targeted drug delivery, hyperthermia, and photodynamic therapy. Poly (lactic-co-glycolic acid) (PLGA)-based materials are frequently used in such setups. This review article gives an overview of the properties of previously reported PLGA nanoparticles (NPs), their behavior in biological systems, and their use for cancer therapy. Strategies are emphasized to target PLGA NPs to the tumor site passively and actively. Furthermore, combination therapies are introduced that enhance the accumulation of NPs and, thereby, their therapeutic efficacy. In this context, the huge number of reports on PLGA NPs used as drug delivery systems in cancer treatment highlight the potential of PLGA NPs as drug carriers for cancer therapeutics and encourage further translational research.

Mechanobiological Mimicry of Helper T Lymphocytes to Evaluate Cell-Biomaterials Crosstalk

The unique properties of immune cells have inspired many efforts in engineering advanced biomaterials capable of mimicking their behaviors. However, an inclusive model capable of mimicking immune cells in different situations remains lacking. Such models can provide invaluable data for understanding immune-biomaterial crosstalk. Inspired by CD4+ T cells, polymeric microparticles with physicochemical properties similar to naïve and active T cells are engineered. A lipid coating is applied to enhance their resemblance and provide a platform for conjugation of desired antibodies. A novel dual gelation approach is used to tune the elastic modulus and flexibility of particles, which also leads to elongated circulation times. Furthermore, the model is enriched with magnetic particles so that magnetotaxis resembles the chemotaxis of cells. Also, interleukin-2, a proliferation booster, and interferon-γ cytokines are loaded into the particles to manipulate the fates of killer T cells and mesenchymal stem cells, respectively. The penetration of these particles into 3D environments is studied to provide in vitro models of immune-biomaterials crosstalk. This biomimicry model enables optimization of design parameters required for engineering more efficient drug carriers and serves as a potent replica for understanding the mechanical behavior of immune cells.

Polyserotonin Nanoparticles as Multifunctional Materials for Biomedical Applications

Serotonin-based nanoparticles represent a class of previously unexplored multifunctional nanoplatforms with potential biomedical applications. Serotonin, under basic conditions, self-assembles into monodisperse nanoparticles via autoxidation of serotonin monomers. To demonstrate potential applications of polyserotonin nanoparticles for cancer therapeutics, we show that these particles are biocompatible, exhibit photothermal effects when exposed to near-infrared radiation, and load the chemotherapeutic drug doxorubicin, releasing it contextually and responsively in specific microenvironments. Quantum mechanical and molecular dynamics simulations were performed to interrogate the interactions between surface-adsorbed drug molecules and polyserotonin nanoparticles. To investigate the potential of polyserotonin nanoparticles for in vivo targeting, we explored their nano-bio interfaces by conducting protein corona experiments. Polyserotonin nanoparticles had reduced surface-protein interactions under biological conditions compared to polydopamine nanoparticles, a similar polymer material widely investigated for related applications. These findings suggest that serotonin-based nanoparticles have advantages as drug-delivery platforms for synergistic chemo- and photothermal therapy associated with limited nonspecific interactions.

Current developments and applications of microfluidic technology toward clinical translation of nanomedicines

Nanoparticulate drug delivery systems hold great potential for the therapy of many diseases, especially cancer. However, the translation of nanoparticulate drug delivery systems from academic research to industrial and clinical practice has been slow. This slow translation can be ascribed to the high batch-to-batch variations and insufficient production rate of the conventional preparation methods, and the lack of technologies for rapid screening of nanoparticulate drug delivery systems with high correlation to the in vivo tests. These issues can be addressed by the microfluidic technologies. For example, microfluidics can not only produce nanoparticles in a well-controlled, reproducible, and high-throughput manner, but also create 3D environments with continuous flow to mimic the physiological and/or pathological processes. This review provides an overview of the microfluidic devices developed to prepare nanoparticulate drug delivery systems, including drug nanosuspensions, polymer nanoparticles, polyplexes, structured nanoparticles and theranostic nanoparticles. We also highlight the recent advances of microfluidic systems in fabricating the increasingly realistic models of the in vivo milieu for rapid screening of nanoparticles. Overall, the microfluidic technologies offer a promise approach to accelerate the clinical translation of nanoparticulate drug delivery systems.

Collagenous matrix supported by a 3D-printed scaffold for osteogenic differentiation of dental pulp cells

OBJECTIVE

A systematic characterization of hybrid scaffolds, fabricated based on combinatorial additive manufacturing technique and freeze-drying method, is presented as a new platform for osteoblastic differentiation of dental pulp cells (DPCs).

METHODS

The scaffolds were consisted of a collagenous matrix embedded in a 3D-printed beta-tricalcium phosphate (β-TCP) as the mineral phase. The developed construct design was intended to achieve mechanical robustness owing to 3D-printed β-TCP scaffold, and biologically active 3D cell culture matrix pertaining to the Collagen extracellular matrix. The β-TCP precursor formulations were investigated for their flow-ability at various temperatures, which optimized for fabrication of 3D printed scaffolds with interconnected porosity. The hybrid constructs were characterized by 3D laser scanning microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and compressive strength testing.

RESULTS

The in vitro characterization of scaffolds revealed that the hybrid β-TCP/Collagen constructs offer superior DPCs proliferation and alkaline phosphatase (ALP) activity compared to the 3D-printed β-TCP scaffold over three weeks. Moreover, it was found that the incorporation of TCP into the Collagen matrix improves the ALP activity.

SIGNIFICANCE

The presented results converge to suggest the developed 3D-printed β-TCP/Collagen hybrid constructs as a new platform for osteoblastic differentiation of DPCs for craniomaxillofacial bone regeneration.

Microfluidic-assisted fabrication of carriers for controlled drug delivery

The microfluidic technique has brought unique opportunities toward the full control over the production processes for drug delivery carriers, owing to the miniaturisation of the fluidic environment. In comparison to the conventional batch methods, the microfluidic setup provides a range of advantages, including the improved controllability of material characteristics, as well as the precisely controlled release profiles of payloads. This review gives an overview of different fluidic principles used in the literature to produce either polymeric microparticles or nanoparticles, focusing on the materials that could have an impact on drug delivery. We also discuss the relations between the particle size and size distribution of the obtained carriers, and the design and configuration of the microfluidic setups. Overall, the use of microfluidic technologies brings exciting opportunities to expand the body of knowledge in the field of controlled drug delivery and great potential to clinical translation of drug delivery systems.

Controllable synthesis of functional nanoparticles by microfluidic platforms for biomedical applications - a review

Nanoparticles have drawn significant attention in biomedicine due to their unique optical, thermal, magnetic and electrical properties which are highly related to their size and morphologies. Recently, microfluidic systems have shown promising potential to modulate critical stages in nanosynthesis, such as nucleation, growth and reaction conditions so that the size, size distribution, morphology, and reproducibility of nanoparticles are optimized in a high throughput manner. In this review, we put an emphasis on a decade of developments of microfluidic systems for engineering nanoparticles in various applications including imaging, biosensing, drug delivery, and theranostic applications.

Microfluidics-mediated assembly of functional nanoparticles for cancer-related pharmaceutical applications

The controlled synthesis of functional nanoparticles with tunable structures and properties has been extensively investigated for cancer treatment and diagnosis. Among a variety of methods for fabrication of nanoparticles, microfluidics-based synthesis enables enhanced mixing and precise fluidic modulation inside microchannels, thus allowing for the flow-mediated production of nanoparticles in a controllable manner. This review focuses on recent advances of using microfluidic devices for the synthesis of drug-loaded nanoparticles with specific characteristics (such as size, composite, surface modification, structure and rigidity) for enhanced cancer treatment and diagnosis as well as to investigate the bio-nanoparticle interaction. The discussion on microfluidics-based synthesis may shed light on the rational design of functional nanoparticles for cancer-related pharmaceutical applications.