Tri-Needle Coaxial Electrospray Engineering of Magnetic Polymer Yolk-Shell Particles Possessing Dual-Imaging Modality, Multiagent Compartments, and Trigger Release Potential

Particulate atomisation design methods for the development and engineering of advanced drug delivery systems: A review

The role and opportunities presented by particulate technologies (due to novel processing methods and advanced materials) have multiplied over the last few decades, leading to promising and ideal properties for drug delivery. For example, the dissolution and bioavailability of poorly soluble drug substances and achieving site- specific drug delivery with a desired release profile are crucial aspects of forming (to some extent) state-of-the-art platforms. Atomisation techniques are intended to achieve efficient control over particle size, improved processing time, improved drug loading efficiency, and the opportunity to encapsulate a broad range of viable yet sensitive therapeutic moieties. Particulate engineering through atomization is accomplished by employing various mechanisms such as air, no air, centrifugal, electrohydrodynamic, acoustic, and supercritical fluid driven processes. These driving forces overcome capillary stresses (e.g., liquid viscosity, surface tension) and transform formulation media (liquid) into fine droplets. More frequently, solvent removal, multiple methods are included to reduce the final size distribution. Nevertheless, a thorough understanding of fluid mechanics, thermodynamics, heat, and mass transfer is imperative to appreciate and predict outputs in real time. More so, in recent years, several advancements have been introduced to improve such processes through complex particle design coupled with quality by-design (QbD) yielding optimal particulate geometry in a predictable manner. Despite these valuable and numerous advancements, atomisation techniques face difficulty scaling up from laboratory scales to manufacturing industry scales. This review details the various atomisation techniques (from design to mechanism) along with examples of drug delivery systems developed. In addition, future perspectives and bottlenecks are provided while highlighting current and selected seminal developments in the field.

Novel erythrocyte-shaped electrosprayed nanoparticles for co-delivery of paclitaxel and osimertinib: Preparation, characterization, and evaluation

In this work, novel erythrocyte-shaped electrosprayed nanoparticles (EENPs) were designed and constructed by tri-axial electrospraying technique with PEG as the outer layer, PLGA as the middle drugs (paclitaxel [PTX] and osimertinib [OSI]) carrier layer and air as the inner layer. The prepared EENP were characterized and evaluated based on their spectral and morphological attributes. After the PTX/OSI ratio and process optimization, the EENP has inspiring features, including nanoscale size, erythrocyte morphology with a concave disk shape, and satisfactory drug loading (DL) and encapsulation efficiency (EE). In vitro drug release showed that PTX and OSI in the formulation were released in the same ratio, and the cumulative release percentage at 24 h was close to 80 %. Furthermore, the TGIR in the EENP formulation group exceeded 90 %, approximately 3.8-fold higher than that in the free drug group. In summary, we developed an erythrocyte three-core-shell nanoparticle for the co-delivery of PTX and OSI, providing a potential chemotherapeutic delivery system for the treatment of breast cancer.

Microgels for Cell Delivery in Tissue Engineering and Regenerative Medicine

Microgels prepared from natural or synthetic hydrogel materials have aroused extensive attention as multifunctional cells or drug carriers, that are promising for tissue engineering and regenerative medicine. Microgels can also be aggregated into microporous scaffolds, promoting cell infiltration and proliferation for tissue repair. This review gives an overview of recent developments in the fabrication techniques and applications of microgels. A series of conventional and novel strategies including emulsification, microfluidic, lithography, electrospray, centrifugation, gas-shearing, three-dimensional bioprinting, etc. are discussed in depth. The characteristics and applications of microgels and microgel-based scaffolds for cell culture and delivery are elaborated with an emphasis on the advantages of these carriers in cell therapy. Additionally, we expound on the ongoing and foreseeable applications and current limitations of microgels and their aggregate in the field of biomedical engineering. Through stimulating innovative ideas, the present review paves new avenues for expanding the application of microgels in cell delivery techniques.

Yolk-shell smart polymer microgels and their hybrids: fundamentals and applications

Yolk-shell microgels and their hybrids have attained great importance in modern-day research owing to their captivating features and potential uses. This manuscript provides the strategies for preparation, classification, properties and current applications of yolk-shell microgels and their hybrids. Some of the yolk-shell microgels and their hybrids are identified as smart polymer yolk-shell microgels and smart hybrid microgels, respectively, as they react to changes in particular environmental stimuli such as pH, temperature and ionic strength of the medium. This unique behavior makes them a perfect candidate for utilization in drug delivery, selective catalysis, adsorption of metal ions, nanoreactors and many other fields. This review demonstrates the contemporary progress along with suggestions and future perspectives for further research in this specific field.

Recent advances of electrospray technique for multiparticulate preparation: Drug delivery applications

The electrospray (ES) technique has proven to be an effective and a versatile approach for crafting drug delivery carriers with diverse dimensions, multiple layers, and varying morphologies. Achieving the desired particle properties necessitates careful optimization of various experimental parameters. This review delves into the most prevalent ES system configurations employed for this purpose, such as monoaxial, coaxial, triaxial, and multi-needle setups with solid or liquid collector. In addition, this work underscores the significance of ES in drug delivery carriers and its remarkable ability to encapsulate a wide spectrum of therapeutic agents, including drugs, nucleic acids, proteins, genes and cells. Depth examination of the critical parameters governing the ES process, including the choice of polymer, surface tension, voltage settings, needle size, flow rate, collector types, and the collector distance was conducted with highlighting on their implications on particle characteristics, encompassing morphology, size distribution, and drug encapsulation efficiency. These insights illuminate ES's adaptability in customizing drug delivery systems. To conclude, this review discusses ES process optimization strategies, advantages, limitations and future directions, providing valuable guidance for researchers and practitioners navigating the dynamic landscape of modern drug delivery systems.

Microfluidics: Insights into Intestinal Microorganisms

Microfluidics is a system involving the treatment or manipulation of microscale (10^-9 to 10^-18 L) fluids using microchannels (10 to 100 μm) contained on a microfluidic chip. Among the different methodologies used to study intestinal microorganisms, new methods based on microfluidic technology have been receiving increasing attention in recent years. The intestinal tracts of animals are populated by a vast array of microorganisms that have been established to play diverse functional roles beneficial to host physiology. This review is the first comprehensive coverage of the application of microfluidics technology in intestinal microbial research. In this review, we present a brief history of microfluidics technology and describe its applications in gut microbiome research, with a specific emphasis on the microfluidic technology-based intestine-on-a-chip, and also discuss the advantages and application prospects of microfluidic drug delivery systems in intestinal microbial research.

Core-shell microparticles: From rational engineering to diverse applications

Core-shell microparticles, composed of solid, liquid, or gas bubbles surrounded by a protective shell, are gaining considerable attention as intelligent and versatile carriers that show great potential in biomedical fields. In this review, an overview is given of recent developments in design and applications of biodegradable core-shell systems. Several emerging methodologies including self-assembly, gas-shearing, and coaxial electrospray are discussed and microfluidics technology is emphasized in detail. Furthermore, the characteristics of core-shell microparticles in artificial cells, drug release and cell culture applications are discussed and the superiority of these advanced multi-core microparticles for the generation of artificial cells is highlighted. Finally, the respective developing orientations and limitations inherent to these systems are addressed. It is hoped that this review can inspire researchers to propel the development of this field with new ideas.

Electrohydrodynamic atomisation driven design and engineering of opportunistic particulate systems for applications in drug delivery, therapeutics and pharmaceutics

Electrohydrodynamic atomisation (EHDA) technologies have evolved significantly over the past decade; branching into several established and emerging healthcare remits through timely advances in the engineering sciences and tailored conceptual process designs. More specifically for pharmaceutical and drug delivery spheres, electrospraying (ES) has presented itself as a high value technique enabling a plethora of different particulate structures. However, when coupled with novel formulations (e.g. co-flows) and innovative device aspects (e.g., materials and dimensions), core characteristics of particulates are manipulated and engineered specifically to deliver an application driven need, which is currently lacking, ranging from imaging and targeted delivery to controlled release and sensing. This demonstrates the holistic nature of these emerging technologies; which is often overlooked. Parametric driven control during particle engineering via the ES method yields opportunistic properties when compared to conventional methods, albeit at ambient conditions (e.g., temperature and pressure), making this extremely valuable for sensitive biologics and molecules of interest. Furthermore, several processing (e.g., flow rate, applied voltage and working distance) and solution (e.g., polymer concentration, electrical conductivity and surface tension) parameters impact ES modes and greatly influence the production of resulting particles. The formation of a steady cone-jet and subsequent atomisation during ES fabricates particles demonstrating monodispersity (or near monodispersed), narrow particle size distributions and smooth or textured morphologies; all of which are successfully incorporated in a one-step process. By following a controlled ES regime, tailored particles with various intricate structures (hollow microspheres, nanocups, Janus and cell-mimicking nanoparticles) can also be engineered through process head modifications central to the ES technique (single-needle spraying, coaxial, multi-needle and needleless approaches). Thus, intricate formulation design, set-up and combinatorial engineering of the EHDA process delivers particulate structures with a multitude of applications in tissue engineering, theranostics, bioresponsive systems as well as drug dosage forms for specific delivery to diseased or target tissues. This advanced technology has great potential to be implemented commercially, particularly on the industrial scale for several unmet pharmaceutical and medical challenges and needs. This review focuses on key seminal developments, ending with future perspectives addressing obstacles that need to be addressed for future advancement.

An Overview on Atomization and Its Drug Delivery and Biomedical Applications

Atomization is an intricate operation involving unstable and complex networks with rupture and fusion of liquid molecules. There are diverse details that typify the spray formation, which are the technique and configuration of the atomization process, dimension and structure of the nozzle, experimental parameters, etc. Ultimately, the process generates fine sprays from the bulk of a liquid. Some examples of atomization that we come across in our day-to-day life are antiperspirant or hair spray, shower head, garden sprinkler, or cologne mist. In this review paper we are briefly discussing the theoretical steps taking place in an atomization technique. The instabilities of the jet and sheet are explained to understand the underlying theory that breaks the jet or sheet into droplets. Different types of atomization processes based on the energy sources are also summarized to give an idea about the advantages and disadvantages of these techniques. We are also discussing the various biomedical applications of the electrohydrodynamic atomization and its potential to use as a drug delivery system. In short, this paper is trying to demonstrate the diverse applications of atomization to show its potency as a user friendly and cost-effective technique for various purposes.

Controlled Formation of All-Aqueous Janus Droplets by Liquid-Liquid Phase Separation of an Aqueous Three-Phase System

Janus droplets have been demonstrated in a wide range of applications, ranging from drug delivery, to biomedical imaging, to bacterial detection. However, existing fabrication strategies often involve nonaqueous solvents, such as organic solvent or oil, which largely limits their use in fields that require a high degree of biocompatibility. Here, we present a method to achieve all-aqueous Janus droplets by liquid-liquid phase separation of an aqueous three-phase system (A3PS). An aqueous droplet containing two initially miscible polymers is first injected into an aqueous solution of another concentrated polymer, and then it spontaneously phase-separates into a Janus droplet due to the diffusive mass exchange between the drop and bulk phases during equilibration. To achieve continuous generation of the Janus droplets, the A3PS is further integrated with microfluidics and electrospray. The size and shape of the phase-separated Janus droplets can be easily controlled by tuning the operation parameters, such as the flow rate and/or the initial composition of the drop phases. Dumbbell-shaped and snowman-shaped Janus droplets with average sizes between 100 and 400 μm can be generated by both coflow microfluidics and electrospray. In particular, the phase-separated Janus droplets can simultaneously load two different liposomes into each compartment, which are promising carriers for combination drugs. The obtained Janus droplets are superior templates for biocompatible materials, which can serve as building blocks such as high-order droplet patterns for constructing advanced biomaterials.

Structured micro/nano materials synthesized via electrospray: a review

The development of synthetic methods for micro/nano materials with precisely controlled structures, morphologies, and local compositions is of great importance for the advancement of modern nanotechnology. The electrospray method is a "platform" approach for the preparation of a broad range of micro-/nanostructures; electrospray is simple and scalable. This review summarizes recent research on the micro-/nanostructures prepared via the electrospray route. These include spherical structures (e.g. simple, porous, Janus, and core-shell particles), non-spherical structures (e.g. red blood cell-like and spindle-like particles, multi-compartment microrods, 2D holey nanosheets, and nanopyramids), and assembled structures. The experimental details, underlying physical/chemical principles, and key benefits of these structures are comprehensively discussed. The effects and importance of nozzle design, properties of feeding solutions (e.g. concentration of solute, polymer additives, solvent/nonsolvent combinations), working environment (e.g. temperature and humidity), and types of collection media are highlighted.

Rational design of yolk-shell nanostructures for drug delivery

Yolk-shell nanoparticles (YSNPs) are a new class of hollow nanostructures, and their unique properties can be utilized in drug delivery systems. The recent progress in YSNPs-based carriers is highlighted in drug delivery systems. Doxorubicin hydrochloride, ceftriaxone sodium, and methotrexate are three of the most common drugs that are used in this field. According to the reported studies, the materials used most often as yolk-shells are magnetic nanoparticles and polymers. The used methods for synthesizing a diverse array of YSNPs are classified based on their core structures. Various properties of YSNPs include their high drug-loading capacity, and their ability to decrease drug toxicity and satisfactorily and efficiently release drugs.

Theranostics Based on Magnetic Nanoparticles and Polymers: Intelligent Design for Efficient Diagnostics and Therapy

Theranostics is a fast-growing field due to demands for new, efficient therapeutics which could be precisely delivered to the target site using multimodal imaging with enhancing auxiliary actions. In this review article we discuss theranostic nanoplatforms containing polymers and magnetic nanoparticles along with other components. Magnetic nanoparticles allow for both diagnostic and therapeutic (hyperthermia) capabilities, while polymers can be reservoirs for drugs and are easily functionalized for cell targeting. We focus on the most important design strategies to achieve optimal theranostic effects as well as the roles of different components included in theranostics, reviewing the literature from the last 5 years.

Influence of a Coaxial Electrospraying System on the n-Hexadecane/Polycaprolactone Phase Change Microcapsules Properties

Electrospraying is considered to be a green, high-efficiency method for synthesizing phase change microcapsules (mPCMs) for possible applications in the fields of energy storage and thermal regulation. In this study, a coaxial nozzle was used to prepare n-hexadecane/polycaprolactone (PCL) microparticles. The objectives of this study were to investigate the influence of working parameters and solutions on morphology, particle size, thermal properties and encapsulation efficiency. Thus, three theoretical loading contents in n-hexadecane (30%, 50% and 70% w/w) and two concentrations of PCL (5 and 10% w/v) were used. The structures, morphologies and thermal properties of mPCMs were characterized by optical microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). Spherical microcapsules with a mean diameter of 10–20 µm were prepared. The increased concentration of n-hexadecane and PCL resulted in a change in the particle size distribution from a poly-disperse to monodisperse size distribution and in a change in the surface state from porous to non-porous. In addition, higher encapsulation efficiency (96%) and loading content (67%) were achieved by the coaxial nozzle using the high core-shell ratio (70/30) and 10% w/v of PCL. The latent heat of the mPCMs reached about 134 J.g⁻¹. In addition, it was also observed that the thermal stability was improved by using a coaxial system rather than a single nozzle.

Fabrication of Polymeric Microparticles by Electrospray: The Impact of Experimental Parameters

Microparticles (MPs) with controlled morphologies and sizes have been investigated by several researchers due to their importance in pharmaceutical, ceramic, cosmetic, and food industries to just name a few. In particular, the electrospray (ES) technique has been shown to be a viable alternative for the development of single particles with different dimensions, multiple layers, and varied morphologies. In order to adjust these properties, it is necessary to optimize different experimental parameters, such as polymer solvent, voltage, flow rate (FR), type of collectors, and distance between the collector and needle tip, which will all be highlighted in this review. Moreover, the influence and contributions of each of these parameters on the design and fabrication of polymeric MPs are described. In addition, the most common configurations of ES systems for this purpose are discussed, for instance, the main configuration of an ES system with monoaxial, coaxial, triaxial, and multi-capillary delivery. Finally, the main types of collectors employed, types of synthesized MPs and their applications specifically in the pharmaceutical and biomedical fields will be emphasized. To date, ES is a promising and versatile technology with numerous excellent applications in the pharmaceutical and biomaterials field and such MPs generated should be employed for the improved treatment of cancer, healing of bone, and other persistent medical problems.

Multifunctional Magnetic Resonance Imaging Probes

Magnetic resonance imaging is characterized by high spatial resolution and unsurpassed soft tissue discrimination. Development and characterization of both intrinsic and extrinsic magnetic resonance (MR) imaging probes in the last decade has further strengthened the pivotal role MR imaging holds in the assessment of cancer in preclinical and translational settings. Sophisticated chemical modifications of a variety of nanoparticulate probes hold the potential to deliver valuable multifunctional tools applicable in diagnostics and/or treatment in human oncology. MR imaging suffers from a lack of sensitivity achievable by, e.g., nuclear medicine imaging methods. Advantages of including additional functionality/functionalities in a probe suitable for MR imaging are thus numerous, comprising the addition of fundamentally different imaging information (diagnostics), drug delivery (therapy), or the combination of both (theranostics). In recent years, we have witnessed a plethora of preclinical multimodal or multifunctional imaging probes being published mainly as proof-of-principle studies, yet only a handful are readily applicable in clinical settings. This chapter summarizes recent innovations in the development of multifunctional MR imaging probes and discusses the suitability of these probes for clinical transfer.

Surface-initiated polymerization for the preparation of magnetic polymer composites

A surface-initiated polymerization method is shown for the preparation of magnetic polymer composites with the good encapsulation of magnetic materials.

Encapsulation of Plant-derived Bioactive Ingredients through Electrospraying for Nutraceuticals and Functional Foods Applications

The electrospraying technique, which consists of electrohydrodynamic atomization of polymeric fluids, can be used to generate dry nano- and microparticles by subjecting a polymer solution, suspension or melt to a high voltage (typically in the range of 7-20 kV) electric field. This potential can be exploited for developing nano- and microencapsulation structures under mild temperature conditions. Thus, it constitutes a promising alternative to conventional microencapsulation techniques for sensitive ingredients, like most plant-derived bioactive compounds, especially for their application in the food sector. Given the importance of plants as one of the major sources of dietary bioactive compounds, significant attention has been recently paid to research the encapsulation of phytochemicals through novel techniques such as electrospraying, aiming to provide new tools for the development of innovative functional food products and nutraceuticals. In this review, the latest advances in the application of electrospraying for nano- and microencapsulation of phytochemicals are discussed, with a focus on their potential use in the food sector.

Electrospun nanofibers as versatile platform in antimicrobial delivery: current state and perspectives

Nanotechnology has attracted increasing interest in different aspects of biotechnology. The fabrication of electrospun nanofibers (NFs) containing antibacterial agents for antimicrobial applications has been significantly enhanced in recent years. In the current review, various electrospun NFs with antimicrobial properties were introduced and evaluated. The main focus was on the recent developments and applications of antimicrobial electrospun NFs incorporated with different antimicrobial agents, including metal nanoparticles (NPs), antibiotics, quaternized ammonium compounds, triclosan, herbal extracts, carbon nanomaterials, and antimicrobial biopolymers with inherent antimicrobial properties. The search results revealed that antimicrobial containing electrospun NFs had enhanced antimicrobial performance with various biomedical applications compared to the traditional antimicrobial materials. According to the reported results, most of the studies were of an investigative nature and were mostly based on in vitro tests. Hence, further examination on in vivo clinical performance of these antimicrobial NFs seems necessary. However, these antimicrobial NFs appear to have the potential to achieve clinical usefulness and commercial production in the near future.

The Process⁻Property⁻Performance Relationship of Medicated Nanoparticles Prepared by Modified Coaxial Electrospraying

In pharmaceutical nanotechnology, the intentional manipulation of working processes to fabricate nanoproducts with suitable properties for achieving the desired functional performances is highly sought after. The following paper aims to detail how a modified coaxial electrospraying has been developed to create ibuprofen-loaded hydroxypropyl methylcellulose nanoparticles for improving the drug dissolution rate. During the working processes, a key parameter, i.e., the spreading angle of atomization region (θ, °), could provide a linkage among the working process, the property of generated nanoparticles and their functional performance. Compared with the applied voltage (V, kV; D = 2713 - 82V with RθV2 = 0.9623), θ could provide a better correlation with the diameter of resultant nanoparticles (D, nm; D = 1096 - 5θ with RDθ2 = 0.9905), suggesting a usefulness of accurately predicting the nanoparticle diameter. The drug released from the electrosprayed nanoparticles involved both erosion and diffusion mechanisms. A univariate quadratic equation between the time of releasing 95% of the loaded drug (t, min) and D (t = 38.7 + 0.097D - 4.838 × 105D2 with a R2 value of 0.9976) suggests that the nanoparticle diameter has a profound influence on the drug release performance. The clear process-property-performance relationship should be useful for optimizing the electrospraying process, and in turn for achieving the desired medicated nanoparticles.

Electrospraying: Possibilities and Challenges of Engineering Carriers for Biomedical Applications-A Mini Review

Electrospraying, a liquid atomization-based technique, has been used to produce and formulate micro/nanoparticular cargo carriers for various biomedical applications, including drug delivery, biomedical imaging, implant coatings, and tissue engineering. In this mini review, we begin with the main features of electrospraying methods to engineer carriers with various bioactive cargos, including genes, growth factors, and enzymes. In particular, this review focuses on the improvement of traditional electrospraying technology for the fabrication of carriers for living cells and providing a suitable condition for gene transformation. Subsequently, the major applications of the electrosprayed carriers in the biomedical field are highlighted. Finally, we finish with conclusions and future perspectives of electrospraying for high efficiency and safe production.

Porous Yolk-Shell Particle Engineering via Nonsolvent-Assisted Trineedle Coaxial Electrospraying for Burn-Related Wound Healing

Yolk-shell particles (YSPs) have attracted increasing attention from various research fields because of their low density, large surface area, and excellent loading capacity. However, the fabrication of polymer-based porous YSPs remains a great challenge. In this work, multifunctional polycaprolactone YSPs were produced using trineedle coaxial electrospraying with a simple nonsolvent process. TiO₂-Ag nanoparticles and Ganoderma lucidum polysaccharides (GLPs) were encapsulated into the outer shell of the YSPs as the major antibacterial and antioxidant components, whereas iron oxide (Fe₃O₄) nanoparticles were incorporated into the inner core to act as a photothermal agent. The morphology and structure, chemical composition, biocompatibility, antioxidant, and antibacterial effects of the fabricated YSPs, photothermal effects, and the release profile of the encapsulated GLP were studied in vitro. Furthermore, the in vivo wound healing effects of the YSPs and the laser-assisted therapy were explored based on a burn wound model on c57 mice.

Influence of Solvent Selection in the Electrospraying Process of Polycaprolactone

Electrosprayed polycaprolactone (PCL) microparticles are widely used in medical tissueengineering, drug control release delivery, and food packaging due to their prominent structuresand properties. In electrospraying, the selection of a suitable solvent system as the carrier of PCL isfundamental and a prerequisite for the stabilization of electrospraying, and the control ofmorphology and structure of electrosprayed particles. The latter is not only critical for diversifyingthe characteristics of electrosprayed particles and achieving improvement in their properties, butalso promotes the efficiency of the process and deepens the applications of electrosprayed particlesin various fields. In order to make it systematic and more accessible, this review mainly concludesthe effects of different solution properties on the operating parameters in electrospraying on theformation of Taylor cone and the final structure as well as the morphology. Meanwhile,correlations between operating parameters and electrospraying stages are summarized as well.Finally, this review provides detailed guidance on the selection of a suitable solvent systemregarding the desired morphology, structure, and applications of PCL particles.

Architecture of yolk-shell structured mesoporous silica nanospheres for catalytic applications

We report the design and realization of yolk-shell structured nanospheres with periodic mesoporous organosilica (PMO) nanospheres or noble metal nanoparticles encapsulated in mesoporous silica shells via a selective etching method. These architectures have well controlled structure, size and morphology. The yolk-shell structured PMO@SiO2 nanoparticles can be precisely functionalized with different catalytic functionalities, even incompatible acidic and basic groups: the PMO core with amino (-NH2) groups and the mesoporous silica shell with sulfonic acid (-SO3H) groups. As a nanoreactor, the as-synthesized Au@SiO2 nanospheres show faster reduction of 4-nitrophenol than that of nitrobenzene. Furthermore, the prepared PMO-NH2@SiO2-SO3H nanoparticles can be used as bifunctional catalysts with highly efficient catalytic performance for catalyzing the deacetalization-Henry cascade reaction.

Canagliflozin-loaded magnetic nanoparticles as potential treatment of hypoxic tumors in combination with radiotherapy

AIM

To synthesize magnetic nanoparticles loaded with the SGLT2-inhibitor canagliflozin (CANA) and evaluate its anticancer potential under normoxic and hypoxic conditions in combination or not with radiotherapy.

MATERIAL & METHODS

Iron oxide nanoparticles were synthesized via an alkaline hydrolytic precipitation of iron precursor in the presence of poly(methacrylic acid)-graft-poly(ethyleneglycol methacrylate). CANA was conjugated to the nanoparticles using N-ethyl-N'-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide chemistry. The anticancer efficacy of the nanoparticles was evaluated in cancer cell lines and in a mouse PDV C57 tumor model.

RESULTS

In the mouse xenograft cancer model, the combination of CANA-loaded nanoparticles with radiotherapy (in the presence of an external magnetic field at the tumor site) exhibited higher antitumor activity compared with the combination of free CANA with radiotherapy.

CONCLUSION

The results obtained indicate the potential that the combination of selective delivery of a SGLT2 inhibitor such as CANA with radiotherapy holds as an anticancer treatment.

Enhancing Multiple Jets in Electrospinning: The Role of Auxiliary Electrode

An auxiliary electrode introduced in traditional spinneret electrospinning is an effective and powerful technique to improve the production rate of nanofibers. In this work, the effects of the arrangement of auxiliary electrode, applied voltage, injection speed, and the distance between the electrode tip and the spinneret tip (ESD) on the jet number and the morphology of polyvinyl alcohol (PVA) nanofibers were investigated systematically. The results showed that the number of jets firstly increased and then decreased with the increase of applied voltage and ESD, respectively, while increasing with the injection speed in both the auxiliary electrode in the vertical position and parallel position. The average nanofiber diameter decreased with increasing of applied voltage and injection speed, but decreasing in ESD in these two positions. The numerical simulation results revealed that the auxiliary electrode primarily influenced the electric field intensity in the spinning area. This work provides a deep understanding of multiple jets in electrospinning.

Targeting oxidative stress using tri-needle electrospray engineered Ganoderma lucidum polysaccharide-loaded porous yolk-shell particles

Chronic lung diseases (e.g. chronic obstructive pulmonary disease and asthma) are associated with oxidative stress and common treatments include various types of inhalation therapies. In this work Ganoderma lucidum polysaccharide (GLP), a naturally occurring antioxidant is loaded into porous Poly (ε-caprolactone) (PCL) particles using a single step tri-needle coaxial electrospray process (Tri-needle CES); with a view to develop therapies to combat oxidative stress. Based on the core-shell structure of porous yolk shell particles (YSPs), GLP-loaded YSPs displayed a bi-phasic release pattern. In vitro cell studies indicate GLP-loaded porous YSPs display good biocompatibility and positive attributes towards H₂O₂-induced oxidative stress in MRC-5 cells and dramatically attenuate intracellular reactive oxygen species (ROS) levels as well as significantly increase cell viability. In vivo inhalation studies indicate that GLP-loaded porous YSPs can be delivered to deep lung tissue and remain deposited for over 48 h and are subsequently removed by natural clearance mechanisms. Based on current findings GLP-loaded porous YSPs are suitable for pulmonary delivery and display good inhalation therapy potential to treat chronic lung diseases.

Electrical Field Guided Electrospray Deposition for Production of Gradient Particle Patterns

Our previous work demonstrated the uniform particle pattern formation on the substrates using electrical field guided electrospray deposition. In this work, we reported for the first time the fabrication of gradient particle patterns on glass slides using an additional point, line, or bar electrode based on our previous electrospray deposition configuration. We also demonstrated that the polydimethylsiloxane (PDMS) coating could result in the formation of uniform particle patterns instead of gradient particle patterns on glass slides using the same experimental setup. Meanwhile, we investigated the effect of experimental configurations on the gradient particle pattern formation by computational simulation. The simulation results are in line with experimental observations. The formation of gradient particle patterns was ascribed to the gradient of electric field and the corresponding focusing effect. Cell patterns can be formed on the particle patterns deposited on PDMS-coated glass slides. The formed particle patterns hold great promise for high-throughput screening of biomaterial-cell interactions and sensing.

Exogenous stromal derived factor-1 releasing silk scaffold combined with intra-articular injection of progenitor cells promotes bone-ligament-bone regeneration

Anterior cruciate ligament (ACL) is one of the most difficult tissues to heal once injured. Ligament regeneration and tendon-bone junction healing are two major goals of ACL reconstruction. This study aimed to investigate the synergistic therapeutic effects of Stromal cell-derived factor 1 (SDF-1)-releasing collagen-silk (CSF) scaffold combined with intra-articular injection of ligament-derived stem/progenitor cells (LSPCs) for ACL regeneration and the amelioration in the long-term complication of osteoarthritis (OA). The stem cell recruitment ability of CSF scaffold and the multipotency, particularly the tendon forming ability of LSPCs from rabbits were characterized in vitro, while the synergistic effect of the CSF scaffold and LSPCs for ACL regeneration and OA amelioration were investigated in vivo at 1, 3, and 6 months with a rabbit ACL reconstruction model. The CSF scaffold was used as a substitute for the ACL, and LSPCs were injected into the joint cavity after 7 days of the ACL reconstruction. CSF scaffold displayed a controlled release pattern for the encapsulated protein for up to 7 days with an increased stiffness in the mechanical property. LSPCs, which exhibited highly I Collagen and CXCR4 expression, were attracted by SDF-1 and successfully relocated into the CSF scaffold at 1 month in vivo. At 3 and 6 months post-treatment, the CSF scaffold combined with LSPCs (CSFL group) enhanced the regeneration of ACL tissue, and promoted bone tunnel healing. Furthermore, the OA progression was impeded efficiently. Our findings here provided a new strategy that using stem cell recruiting CSF scaffold with tissue-specific stem cells, could be a promising solution for ACL regeneration.

STATEMENT OF SIGNIFICANCE

In this study, we developed a silk scaffold with increased stiffness and SDF-1 controlled release capacity for ligament repair. This advanced scaffold transplantation combined with intra-articular injection of LSPCs (which was isolated from rabbit ligament for the first time in this study) promoted the regeneration of both the tendinous and bone tunnel portion of ACL. This therapeutic strategy also ameliorated cartilage degeneration and reduced the severity of arthrofibrosis. Hence, combining LSPCs injection with SDF-1-releasing silk scaffold is demonstrated as a therapeutic strategy for ACL regeneration and OA treatment in the clinic.

Optimizing Circulating Tumor Cells' Capture Efficiency of Magnetic Nanogels by Transferrin Decoration

Magnetic nanogels (MNGs) are designed to have all the required features for their use as highly efficient trapping materials in the challenging task of selectively capturing circulating tumor cells (CTCs) from the bloodstream. Advantageously, the discrimination of CTCs from hematological cells, which is a key factor in the capturing process, can be optimized by finely tuning the polymers used to link the targeting moiety to the MNG. We describe herein the relationship between the capturing efficiency of CTCs with overexpressed transferrin receptors and the different strategies on the polymer used as linker to decorate these MNGs with transferrin (Tf). Heterobifunctional polyethylene glycol (PEG) linkers with different molecular weights were coupled to Tf in different ratios. Optimal values over 80% CTC capture efficiency were obtained when 3 PEG linkers with a length of 8 ethylene glycol (EG) units were used, which reveals the important role of the linker in the design of a CTC-sorting system.

An Inhalable Powder Formulation Based on Micro- and Nanoparticles Containing 5-Fluorouracil for the Treatment of Metastatic Melanoma

Melanoma is the most aggressive and lethal type of skin cancer, with a poor prognosis because of the potential for metastatic spread. The aim was to develop innovative powder formulations for the treatment of metastatic melanoma based on micro- and nanocarriers containing 5-fluorouracil (5FU) for pulmonary administration, aiming at local and systemic action. Therefore, two innovative inhalable powder formulations were produced by spray-drying using chondroitin sulfate as a structuring polymer: (a) 5FU nanoparticles obtained by piezoelectric atomization (5FU-NS) and (b) 5FU microparticles of the mucoadhesive agent Methocel™ F4M for sustained release produced by conventional spray drying (5FU-MS). The physicochemical and aerodynamic were evaluated in vitro for both systems, proving to be attractive for pulmonary delivery. The theoretical aerodynamic diameters obtained were 0.322 ± 0.07 µm (5FU-NS) and 1.138 ± 0.54 µm (5FU-MS). The fraction of respirable particles (FR%) were 76.84 ± 0.07% (5FU-NS) and 55.01 ± 2.91% (5FU-MS). The in vitro mucoadhesive properties exhibited significant adhesion efficiency in the presence of Methocel™ F4M. 5FU-MS and 5FU-NS were tested for their cytotoxic action on melanoma cancer cells (A2058 and A375) and both showed a cytotoxic effect similar to 5FU pure at concentrations of 4.3 and 1.7-fold lower, respectively.