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

Preparation of capecitabine-poly(p-dioxanone) electrospraying nanoparticles and influence of particle size on their colorectal cancer inhibitive efficiency

Colorectal cancer is the fourth leading cause of cancer-related deaths worldwide. Capecitabine is a chemotherapeutic agent commonly used for the treatment of colon cancer. To realize local sustained release, promote efficient local intracellular transport, and mitigate the systemic toxic effects of capecitabine, a capecitabine prodrug, capecitabine-poly (p-dioxanone) (Cap-PPDO), was successfully synthesized. Cap-PPDO was subsequently processed into nanoscale particles with various diameters using electrospraying to investigate the influence of nanoparticle (NP) size on the therapeutic efficiency of Cap-PPDO NPs. Design Expert Software was used to design an experimental scheme for evaluating the influence of electrospraying parameters on NP size and distribution. The in vitro capecitabine release rate of Cap-PPDO NPs was evaluated, and NPs with a size of approximately 300 nm demonstrated the fastest release rate. However, Cap-PPDO NPs with a size of approximately 300 nm exhibited lower proliferation inhibition against SW480 colorectal cancer compared to those with diameters of 200 and 400 nm. To further elucidate the influence of size, the endocytosis of SW480 cells with respect to these differently sized NPs was investigated using flow cytometry and transmission electron microscopy (TEM), given that endocytosis is an important pathway for the intracellular delivery of nanoparticles. The mechanism underlying the size-dependent therapeutic efficiency of Cap-PPDO NPs was ultimately attributed to the size of the mammalian lysosome. Finally, the therapeutic efficacy of Cap-PPDO NPs of various sizes was verified using a nude mouse model of SW480 cell-transplanted tumors.

Navigating translational research in nanomedicine: A strategic guide to formulation and manufacturing

Over the past two decades, extensive research has focused on both the fundamental and applied aspects of nanomedicine, driven by the compelling advantages that nanoparticles offer over their bulk counterparts. Despite this intensive research effort, fewer than 100 nanomedicines have been approved by the U.S. Food and Drug Administration and the European Medicines Agency since 1989. This disparity highlights a substantial gap in translational research, reflecting the disconnect between the prolific research in nanomedicine and the limited number of products that successfully reach and sustain themselves in the market. For instance, the nanomedicine DepoCyt, which received FDA approval in 1999 for the treatment of lymphomatous meningitis, was discontinued in 2017 due to persistent manufacturing issues. To address similar translational challenges, this review aims to identify and analyse issues related to the formulation design and manufacturing of nanomedicines. It provides an overview of the most prevalent manufacturing technologies and excipients used in nanomedicine production, followed by a critical evaluation of their clinical translatability. Furthermore, the review presents strategies for the rational formulation design and optimization of nanomedicine manufacturing, adhering to the principles of quality-by-design and quality risk management.

Microencapsulation Techniques in HIV Pediatric Formulations: Advances and Future Outlook

The treatment of human immunodeficiency virus (HIV) in children has persistently been complex and tedious on a global scale. This is because adult and pediatric HIV treatments follow a similar therapeutic approach. Due to the dearth of clinically licensed pediatric antiretroviral drug (ARVD) therapy, children with HIV worldwide are prescribed unlicensed drugs each year. This has triggered likelihood of poor drug adherence, therapeutic failure, and even adverse reactions brought on by a variety of factors, including pill size and quantity, which is the main cause of swallowing difficulties, repeated administration of these various ARVDs, many of which have poor solubility and cause severe side effects in children, and unpalatability of the drug, which is one of the criteria for pediatric formulations. Thus, there is a necessity for investigation into several advanced microencapsulation techniques that could curb these challenges. Microencapsulation techniques have explored in drug delivery for encapsulation and manufacture of different nanoparticles that have shown significant potential in mitigating and surmounting different constraints, such as taste masking, enhanced drug solubility and bioavailability, and production of micronized fine powders for treatment of varying diseases. Nevertheless, the usage of these technologies in HIV pediatric formulations has garnered relatively little attention. Thus, this review has paid a keen interest in examining several microencapsulation strategies for potential utilization in the development of HIV pediatric formulations.

Polymeric nanoparticles produced by electrohydrodynamic atomisation for the passive delivery of imatinib

Imatinib is a chemotherapeutic agent known to cause severe side effects when administrated systemically. Encapsulating imatinib in co-polymer poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) offers a targeted drug delivery. In this work, PLGA 50:50 and PLGA 75:25 NPs encapsulated imatinib using the electrohydrodynamic atomisation technique. All particles generated were spherical with a smooth surface with a size distribution of 455±115 nm (PLGA 50:50) and 363±147 nm (PLGA 75:25). Encapsulation of imatinib was shown to be higher than 75 % and was shown to increase the zeta potential of the loaded NPs. The release of imatinib showed an initial burst in the first 12 h, followed by different sustained releases with up to 70 %. Both types of imatinib-loaded NPs' effect on cell viability and their cellular uptake were also studied on A549 cells, and the antiproliferative effect was comparable to that of cells treated with free drugs. Finally, Rhodamine-B-loaded NP-treated cells demonstrated the cellular uptake of NPs.

Preparation and characterization of the injectable pH- and temperature-sensitive pentablock hydrogel containing human growth hormone-loaded chitosan nanoparticles via electrospraying

This research investigated the in vivo gelation, biodegradation, and drug release efficiency of a novel injectable sensitive drug delivery system for human growth hormone (HGh). This composite system comprises pH- and temperature-sensitive hydrogel, designated as oligomer serine-b-poly(lactide)-b-poly(ethylene glycol)-b-poly(lactide)-b-oligomer serine (OS-PLA-PEG-PLA-OS) pentablock copolymer, as matrix and electrosprayed HGh-loaded chitosan (HGh@CS) nanoparticles (NPs) as principal material. The proton nuclear magnetic resonance spectrum of the pH- and temperature-sensitive OS-PLA-PEG-PLA-OS pentablock copolymer hydrogel proved that this copolymer was successfully synthesized. The HGh was encapsulated in chitosan (CS) NPs by an electrospraying system in acetic acid with appropriate granulation parameters. The scanning electron microscopy images and size distribution showed that the HGh@CS NPs formed had an average diameter of 366.1 ± 214.5 nm with a discrete spherical shape and dispersed morphology. The sol-gel transition of complex gel based on HGh@CS NPs and OS-PLA-PEG-PLA-OS pentablock hydrogel was investigated at 15 °C and pH 7.8 in the sol state and gelled at 37 °C and pH 7.4, which is suitable for the physiological conditions of the human body. The HGh release experiment of the composite system was performed in an in vivo environment, which demonstrated the ability to release HGh, and underwent biodegradation within 32 days. The findings of the investigation revealed that the distribution of HGh@CS NPs into the hydrogel matrix not only improved the mechanical properties of the gel matrix but also controlled the drug release kinetics into the systematic bloodstream, which ultimately promotes the desired therapeutic body growth depending on the distinct concentration used.

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.

Electrosprayed Nanoparticles Containing Mangiferin-Rich Extract from Mango Leaves for Cosmeceutical Application

Mango (Mangifera indica L.) is one of the most economically important fruits in Thailand. Mango has been used as a traditional medicine because it possesses many biological activities, such as antioxidant properties, anti-inflammatory properties, microorganism-growth inhibition, etc. Among its natural pharmacologically active compounds, mangiferin is the main active component found in mango leaves. Mangiferin has the potential to treat a variety of diseases due to its multifunctional activities. This study aims to prepare a mangiferin-rich extract (MRE) from mango leaves and develop nanoparticles containing the MRE using an electrospraying technique to apply it in a cosmeceutical formulation. The potential cosmeceutical mechanisms of the MRE were investigated using proteomic analysis. The MRE is involved in actin-filament organization, the positive regulation of cytoskeleton organization, etc. Moreover, the related mechanism to its cosmeceutical activity is metalloenzyme-activity regulation. Nanoparticles were prepared from 0.8% w/v MRE and 2% w/v Eudragit® L100 solution using an electrospraying process. The mean size of the MRE-loaded nanoparticles (MNPs) received was 247.8 nm, with a PDI 0.271. The MRE entrapment by the process was quantified as 84.9%, indicating a high encapsulation efficiency. For the skin-retention study, the mangiferin content in the MNP-containing emulsion-gel membranes was examined and found to be greater than in the membranes of the MRE solution, illustrating that the MNPs produced by the electrospraying technique help transdermal delivery for cosmetic applications.

Advances in Functionalization of Bioresorbable Nanomembranes and Nanoparticles for Their Use in Biomedicine

Bioresorbable nanomembranes (NMs) and nanoparticles (NPs) are powerful polymeric materials playing an important role in biomedicine, as they can effectively reduce infections and inflammatory clinical patient conditions due to their high biocompatibility, ability to physically interact with biomolecules, large surface area, and low toxicity. In this review, the most common bioabsorbable materials such as those belonging to natural polymers and proteins for the manufacture of NMs and NPs are reviewed. In addition to biocompatibility and bioresorption, current methodology on surface functionalization is also revisited and the most recent applications are highlighted. Considering the most recent use in the field of biosensors, tethered lipid bilayers, drug delivery, wound dressing, skin regeneration, targeted chemotherapy and imaging/diagnostics, functionalized NMs and NPs have become one of the main pillars of modern biomedical applications.

The influence of the ultrasonic treatment of working fluids on electrospun amorphous solid dispersions

Based on a working fluid consisting of a poorly water-soluble drug and a pharmaceutical polymer in an organic solvent, electrospinning has been widely exploited to create a variety of amorphous solid dispersions However, there have been very few reports about how to prepare the working fluid in a reasonable manner. In this study, an investigation was conducted to determine the influences of ultrasonic fluid pretreatment on the quality of resultant ASDs fabricated from the working fluids. SEM results demonstrated that nanofiber-based amorphous solid dispersions from the treated fluids treated amorphous solid dispersions exhibited better quality than the traditional nanofibers from untreated fluids in the following aspects: 1) a straighter linear morphology; 2) a smooth surface; and 3) a more evener diameter distribution. The fabrication mechanism associated with the influences of ultrasonic treatments of working fluids on the resultant nanofibers' quality is suggested. Although XRD and ATR-FTIR experiments clearly verified that the drug ketoprofen was homogeneously distributed all over the TASDs and the traditional nanofibers in an amorphous state regardless of the ultrasonic treatments, the in vitro dissolution tests clearly demonstrated that the TASDs had a better sustained drug release performance than the traditional nanofibers in terms of the initial release rate and the sustained release time periods.

An eco-friendly chitosan/cellulose acetate hybrid nanostructure containing Ziziphora clinopodioides essential oils for active food packaging applications

This work presents the fabrication and characterization of a hybrid nanostructure, Ziziphora clinopodioides essential oils (ZEO)-loaded chitosan nanoparticles (CSNPs-ZEO) embedded into cellulose acetate (CA) nanofibers (CA-CSNPs-ZEO). The CSNPs-ZEO were first synthesized through the ionic gelation method. Then, through simultaneous electrospraying and electrospinning processes, the nanoparticles were embedded in the CA nanofibers. The morphological and physicochemical characteristics of the prepared nanostructures were evaluated using different methods, including scanning electron microscopy (SEM), water vapor permeability (WVP), moisture content (MC), mechanical testing, differential scanning calorimetry (DSC), and release profile studies. The antibacterial activity of the nanostructures was explored on raw beef as a food model during 12 days of storage at 4 °C. The obtained results indicated the successful synthesis of CSNPs-ZEO nanoparticles with an average size of 267 ± 6 nm and their incorporation into the nanofibers matrix. Moreover, the CA-CSNPs-ZEO nanostructure showed a lower water vapor barrier and higher tensile strength compared with ZEO-loaded CA (CA-ZEO) nanofiber. The CA-CSNPs-ZEO nanostructure also exhibited strong antibacterial activity, which effectively extended the shelf-life of raw beef. The results demonstrated a strong potential for innovative hybrid nanostructures in active packaging to maintain the quality of perishable food products.

Micro and nanotechnologies: The little formulations that could

The first publication of micro- and nanotechnology in medicine was in 1798 with the use of the Cowpox virus by Edward Jenner as an attenuated vaccine against Smallpox. Since then, there has been an explosion of micro- and nanotechnologies for medical applications. The breadth of these micro- and nanotechnologies is discussed in this piece, presenting the date of their first report and their latest progression (e.g., clinical trials, FDA approval). This includes successes such as the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines from Pfizer, Moderna, and Janssen (Johnson & Johnson) as well as the most popular nanoparticle therapy, liposomal Doxil. However, the enormity of the success of these platforms has not been without challenges. For example, we discuss why the production of Doxil was halted for several years, and the bankruptcy of BIND therapeutics, which relied on a nanoparticle drug carrier. Overall, the field of micro- and nanotechnology has advanced beyond these challenges and continues advancing new and novel platforms that have transformed therapies, vaccines, and imaging. In this review, a wide range of biomedical micro- and nanotechnology is discussed to serve as a primer to the field and provide an accessible summary of clinically relevant micro- and nanotechnology platforms.

Electrohydrodynamic 3D Printing of Aqueous Solutions

Among the various electrohydrodynamic (EHD) processing techniques, electrowriting (EW) produces the most complex 3D structures. Aqueous solution EW similarly retains the potential for additive manufacturing well-resolved 3D structures, while providing new opportunities for processing biologically derived polymers and eschewing organic solvents. However, research on aqueous-based EHD processing is still limited. To summarize the field and advocate for increased use of aqueous bio-based materials, this review summarizes the most significant contributions of aqueous solution processing. Special emphasis has been placed on understanding the effects of different printing parameters, the prospects for 3D processing new materials, and future challenges.

Micro-/bio-/nano-/syn-encapsulations and co-treatments of bioactive microbial feed supplementation in augmenting finfish health and aquaculture nutrition: a review

Finfish and fish products are globally the most acknowledged health-promoting foods. The rising incidence of pathogenic and disease outbreaks have had a sizeable impact on aquaculture. Microbial supplementation of food in the form of probiotics, prebiotics, and their controlled release combinations (=co-encapsulations) as 'synbiotics' is noted for its significant biotherapeutic and health benefits. Supplementation of probiotic microbial feed additives in the fish diet claims to improve fish health by modulation of resident intestinal microbiota and by introducing healthy microbiota procured from an exogenous source, capable of combating pathogens, improving nutrient uptake, assimilation, growth as well as survival. Prebiotics are selectively digestible substrates beneficially used by host gut microbes to enhance probiotic effects. Formulating a fish diet with augmented probiotics and prebiotic microbial bio-supplements can ensure a sustainable alternative for establishing fish health in a naturally susceptible aquaculture scenario. Micro-encapsulation, co-encapsulation, and nano-encapsulation are novel strategies of biotechnical interventions in functional feeds for finfish. These aim to improve probiotic persistence, survivability, and efficacy in commercial formulations during probiotic transit through the host-gut environment. This review discusses the importance of co-treatment and encapsulation strategies for improving probiotic and prebiotic potential in aquafeed formulations, reliably improving finfish health and nutritional returns from aquaculture, and, consequently, for consumers.

Scalable fabrication, compartmentalization and applications of living microtissues

Living microtissues are used in a multitude of applications as they more closely resemble native tissue physiology, as compared to 2D cultures. Microtissues are typically composed of a combination of cells and materials in varying combinations, which are dictated by the applications' design requirements. Their applications range wide, from fundamental biological research such as differentiation studies to industrial applications such as cruelty-free meat production. However, their translation to industrial and clinical settings has been hindered due to the lack of scalability of microtissue production techniques. Continuous microfluidic processes provide an opportunity to overcome this limitation as they offer higher throughput production rates as compared to traditional batch techniques, while maintaining reproducible control over microtissue composition and size. In this review, we provide a comprehensive overview of the current approaches to engineer microtissues with a focus on the advantages of, and need for, the use of continuous processes to produce microtissues in large quantities. Finally, an outlook is provided that outlines the required developments to enable large-scale microtissue fabrication using continuous processes.

Valorisation of Micro/Nanoencapsulated Bioactive Compounds from Plant Sources for Food Applications Towards Sustainability

The micro- and nanoencapsulation of bioactive compounds has resulted in a large improvement in the food, nutraceutical, pharmaceutical, and agriculture industries. These technologies serve, on one side, to protect, among others, vitamins, minerals, essential fatty acids, polyphenols, flavours, antimicrobials, colorants, and antioxidants, and, on the other hand, to control the release and assure the delivery of the bioactive compounds, targeting them to specific cells, tissues, or organs in the human body by improving their absorption/penetration through the gastrointestinal tract. The food industry has been applying nanotechnology in several ways to improve food texture, flavour, taste, nutrient bioavailability, and shelf life using nanostructures. The use of micro- and nanocapsules in food is an actual trend used mainly in the cereal, bakery, dairy, and beverage industries, as well as packaging and coating. The elaboration of bio capsules with high-value compounds from agro-industrial by-products is sustainable for the natural ecosystem and economically interesting from a circular economy perspective. This critical review presents the principal methodologies for performing micro- and nanoencapsulation, classifies them (top-down and/or bottom-up), and discusses the differences and advantages among them; the principal types of encapsulation systems; the natural plant sources, including agro-industrial by-products, of bioactive compounds with interest for the food industry to be encapsulated; the bioavailability of encapsulates; and the main techniques used to analyse micro- and nanocapsules. Research work on the use of encapsulated bioactive compounds, such as lycopene, hydroxytyrosol, and resveratrol, from agro-industrial by-products must be further reinforced, and it plays an important role, as it presents a high potential for the use of their antioxidant and/or antimicrobial activities in food applications and, therefore, in the food industry. The incorporation of these bioactive compounds in food is a challenge and must be evaluated, not only for their nutritional aspect, but also for the chemical safety of the ingredients. The potential use of these products is an available economical alternative towards a circular economy and, as a consequence, sustainability.

Microfluidic Formulation of Topological Hydrogels for Microtissue Engineering

Microfluidics has recently emerged as a powerful tool in generation of submillimeter-sized cell aggregates capable of performing tissue-specific functions, so-called microtissues, for applications in drug testing, regenerative medicine, and cell therapies. In this work, we review the most recent advances in the field, with particular focus on the formulation of cell-encapsulating microgels of small "dimensionalities": "0D" (particles), "1D" (fibers), "2D" (sheets), etc., and with nontrivial internal topologies, typically consisting of multiple compartments loaded with different types of cells and/or biopolymers. Such structures, which we refer to as topological hydrogels or topological microgels (examples including core-shell or Janus microbeads and microfibers, hollow or porous microstructures, or granular hydrogels) can be precisely tailored with high reproducibility and throughput by using microfluidics and used to provide controlled "initial conditions" for cell proliferation and maturation into functional tissue-like microstructures. Microfluidic methods of formulation of topological biomaterials have enabled significant progress in engineering of miniature tissues and organs, such as pancreas, liver, muscle, bone, heart, neural tissue, or vasculature, as well as in fabrication of tailored microenvironments for stem-cell expansion and differentiation, or in cancer modeling, including generation of vascularized tumors for personalized drug testing. We review the available microfluidic fabrication methods by exploiting various cross-linking mechanisms and various routes toward compartmentalization and critically discuss the available tissue-specific applications. Finally, we list the remaining challenges such as simplification of the microfluidic workflow for its widespread use in biomedical research, bench-to-bedside transition including production upscaling, further in vivo validation, generation of more precise organ-like models, as well as incorporation of induced pluripotent stem cells as a step toward clinical applications.

Exploiting Polymeric Films as a Multipurpose Drug Delivery System: a Review

Polymeric films are drug delivery systems that maintain contact with the delivery tissue and sustain a controlled release of therapeutic molecules. These systems allow a longer time of drug contact with the target site in the case of topical treatments and allow the controlled administration of drugs. They can be manufactured by various methods such as solvent casting, hot melt extrusion, electrospinning, and 3D bioprinting. Furthermore, they can employ various polymers, for example PVP, PVA, cellulose derivatives, chitosan, gelling gum, pectin, and alginate. Its versatility is also applicable to different routes of administration, as it can be administered to the skin, oral mucosa, vaginal canal, and eyeballs. All these factors allow numerous combinations to obtain a better treatment. This review focuses on exploring some possible ways to develop them and some particularities and advantages/disadvantages in each case. It also aims to show the versatility of these systems and the advantages and disadvantages in each case, as they bring the opportunity to develop different medicines to facilitate therapies for the most diverse purposes .

Physical, Chemical, and Biological Properties of Chitosan-Coated Alginate Microparticles Loaded with Porcine Interleukin-1β: A Potential Protein Adjuvant Delivery System

We previously developed chicken interleukin-1β (IL-1β) mutants as single-dose adjuvants that induce protective immunity when co-administered with an avian vaccine. However, livestock such as pigs may require a vaccine adjuvant delivery system that provides long-lasting protection to reduce the need for successive booster doses. Therefore, we developed chitosan-coated alginate microparticles as a carrier for bovine serum albumin (BSA) or porcine IL-1β (pIL-1β) and assessed their physical, chemical, and biological properties. Electrospraying of the BSA-loaded alginate microparticles (BSA/ALG MPs) resulted in an encapsulation efficiency of 50%, and those MPs were then coated with chitosan (BSA/ALG/CHI MPs). Optical and scanning electron microscopy, zeta potential analysis, and Fourier transform infrared spectroscopy were used to characterize these MPs. The BSA encapsulation parameters were applied to ALG/CHI MPs loaded with pIL-1β, which were not cytotoxic to porcine fibroblasts but had enhanced bio-activity over unencapsulated pIL-1β. The chitosan layer of the BSA/ALG/CHI MPs prevented burst release and facilitated sustained release of pIL-1β for at least 28 days. In conclusion, BSA/ALG/CHI MPs prepared as a carrier for pIL-1β may be used as an adjuvant for the formulation of pig vaccines.

Integration of physicochemical, molecular dynamics, and in vitro evaluation of electrosprayed γ-oryzanol-loaded gliadin nanoparticles

Electrospraying is a technique to improve the application and stability of bioactive compounds in food. Here, electrospraying was applied to fabricate gliadin particles incorporated γ-oryzanol. The round particles were obtained, with an average diameter of 481.56 ± 283.74 nm, from scanning electron microscopy. Simulations demonstrated how γ-oryzanol-loaded gliadin particles were unfolded in acetic acid and culminated in their globular shape under an electric field. The results also revealed that γ-oryzanol was present in gliadin particles. Moreover, there was a successful formation of particles with a homogeneous distribution and an enhanced thermostabilization of γ-oryzanol. In food simulants, γ-oryzanol demonstrated an initial burst release, followed by a subsequent, slower release that occurred gradually. Finally, MTT assays showed concentration- and time-dependent inhibitions of γ-oryzanol-loaded gliadin particles on HT-29 cells, with IC₅₀ values of 0.47 and 0.40 mg/mL for 24 and 48 h, respectively. This study described a protocol for developing γ-oryzanol-loaded gliadin particles with enhanced stability, valuable release-behavior, and decreased HT-29 proliferation.

Pharmaceutical-eluting hybrid degradable hydrogel/microparticle loaded sacs for finger joint interpositional arthroplasty

Despite recent advances in medical technology, treatment of chronic osteomyelitis in the small joint of the hand remains challenging. Here, we exploited hybrid biodegradable hydrogel/microparticle/polycaprolactone (PCL) sacs for finger joint interpositional arthroplasty via electrospraying and rotational molding techniques. Degradable Pluronic F127, poly(lactic-co-glycolic acid) (PLGA), and PCL were starting materials for the hydrogels, microparticles, and sac, respectively. Vancomycin, ceftazidime, and lidocaine were the embedded pharmaceuticals. The in vitro and in vivo drug release behaviors of hybrid drug-eluting sacs were assessed. The empirical outcomes show that the size distribution of the electrosprayed vancomycin/ceftazidime/lidocaine PLGA microparticles was 8.25 ± 3.35 μm. Biodegradable PCL sacs offered sustainable and effective release of vancomycin, ceftazidime, and lidocaine, respectively, after 30, 16, and 11 days in vitro. The sacs also discharged high levels of anti-microbial agents for 56 days and analgesics for 14 days in a rabbit knee joint model. The blood urea nitrogen (creatinine) levels remained normal at various time points: 16.5 ± 2.5 mg/dL (0.85 ± 0.24 mg/dL), 20.0 ± 1.4 mg/dL (1.0 ± 0.16 mg/dL), 19.3 ± 2.4 mg/dL (1.13 ± 0.15 mg/dL), and 20.0 ± 2.16 mg/dL (1.0 ± 0.16 mg/dL) at days 7, 14, 21, and 35, respectively. The empirical outcomes of this study suggested that the hybrid biodegradable drug-eluting sacs with extended liberation of pharmaceuticals may find applications in the small joints for post-operative pain relief and infection control.

Resveratrol Microencapsulation into Electrosprayed Polymeric Carriers for the Treatment of Chronic, Non-Healing Wounds

Chronic, non-healing wounds represent a challenging socio-economic burden, demanding innovative approaches for successful wound management. Resveratrol (RSV) represents a promising therapeutic candidate, but its therapeutic efficacy and clinical applicability have been hampered by its rapid degradation and/or depletion. Herein, RSV was encapsulated into poly(ε-caprolactone) (PCL) microparticles by electrospraying with the aim to prolong and preserve RSV’s release/activity, without affecting its therapeutic properties. Electrospraying led to the fabrication of spherical (2 to 10 μm in size), negatively charged (<−1 mV), and quasi-monodisperse (PDI < 0.3) microparticles, with 60% RSV release after 28 days. Microencapsulation of RSV into PCL prevented its photochemical degradation and preserved its antioxidant properties over 72 h. The RSV-PCL microparticles did not exhibit any cytotoxicity on human dermal fibroblasts. RSV released from the microparticles was biologically functional and induced a significant increase in collagen type I deposition. Furthermore, the produced RSV-PCL microparticles reduced the expression of inflammatory (IL-6, IL-8, COX-2) and proteolytic (MMP-2, MMP-9) mediators. Collectively, our data clearly illustrate the potential of electrosprayed polymeric carriers for the sustained delivery of RSV to treat chronic wounds.

Profiling single-molecule reaction kinetics under nanopore confinement

The study of a single-molecule reaction under nanoconfinement is beneficial for understanding the reactive intermediates and reaction pathways. However, the kinetics model of the single-molecule reaction under confinement remains elusive. Herein we engineered an aerolysin nanopore reactor to elaborate the single-molecule reaction kinetics under nanoconfinement. By identifying the bond-forming and non-bond-forming events directly, a four-state kinetics model is proposed for the first time. Our results demonstrated that the single-molecule reaction kinetics inside a nanopore depends on the frequency of individual reactants captured and the fraction of effective collision inside the nanopore confined space. This insight will guide the design of confined nanopore reactors for resolving the single-molecule chemistry, and shed light on the mechanistic understanding of dynamic covalent chemistry inside confined systems such as supramolecular cages, coordination cages, and micelles.

A four-state kinetics model is proposed to reveal the kinetics of a single-molecule reaction under nanopore confinement.

Improved porosity of electrospun poly (Lactic-Co-Glycolic) scaffolds by sacrificial microparticles enhances cellular infiltration compared to sacrificial microfiber

Electrospinning is a technique used to fabricate nano-/microfiber scaffolds for tissue engineering applications. However, a major limitation of electrospun scaffolds is the high packing density of fibers that leads to poor cellular infiltration. Thus, incorporation of a water soluble sacrificial porogen, polyethylene oxide (PEO), was utilized to fine-tune the porous fraction of the scaffolds and decrease fiber packing density. Poly(lactic-co-glycolic) acid (PLGA) scaffolds were either co-electrospun with sacrificial PEO microfibers or co-electrosprayed with sacrificial PEO microparticles at three different extrusion rates to control the relative morphology and dose of PEO. A dose-dependent response in PLGA scaffold bulk porosity and pore area was noted as PEO content was increased. Notably, PLGA scaffolds after removal of sacrificial PEO microparticles significantly increased the porous fraction and pore area approximately 8, 10, and 14% and 46, 20, and 33 μm², respectively, relative to the analogous PEO microfiber scaffold. The tensile properties of the more porous PLGA scaffolds after PEO microparticle removal, remained stable for all extrusion rates of PEO tested, relative to the PLGA scaffolds after PEO microfiber removal. Histological analysis revealed that removal of PEO microparticles significantly increased the depth of cellular migration through the PLGA scaffolds, relative to PEO microfiber scaffolds, with maximum migratory depths of 1120 μm versus 150 μm over 28 days, respectively. Additionally, depth of cellular infiltration responded dose-dependently in the PEO microparticle scaffolds, whereas in the PEO microfiber scaffolds there was no correlation. Further analysis with Masson's Trichrome staining and electron microscopy revealed that collagen density and depth of deposition substantially increased in PLGA scaffolds after removal of PEO microparticles relative to PEO microfibers. Thus, this study demonstrates an effective strategy to control the porous fraction of electrospun scaffolds via the incorporation of sacrificial PEO microparticles, without significant decreases in mechanical properties, thereby enhancing cellular infiltration and subsequent extracellular matrix deposition.

Fabrication of Ropivacaine/Dexamethasone-Eluting Poly(D, L-lactide-co-glycolide) Microparticles via Electrospraying Technique for Postoperational Pain Control

Microencapsulation plays an important role in biomedical technology owing to its particular and attractive characteristics. In this work, we developed ropivacaine and dexamethasone loaded poly(D, L-lactide-co-glycolide) (PLGA) microparticles via electrospraying technique and investigated the release behavior of electrosprayed microparticles. The particle morphology of sprayed particles was assessed using scanning electron microscopy (SEM). The in vitro drug release kinetics were evaluated employing an elution method, and the in vivo pharmaceutical release as well as its efficacy on pain relief were tested using an animal activity model. The microscopic observation suggested that sprayed microparticles exhibit a size distribution of 5-6 µm. Fourier-transform infrared spectrometry and differential scanning calorimetry demonstrated the successful incorporation of pharmaceuticals in the PLGA particulates. The drugs-loaded particles discharged sustainably high concentrations of ropivacaine and dexamethasone at the target region in vivo for over two weeks, and the drug levels in the blood remained low. By adopting the electrospraying technique, we were able to prepare drug-embedded polymeric microparticles with effectiveness and with a sustainable capability for postoperative pain control.

The status and perspectives of nanostructured materials and fabrication processes for wearable piezoresistive sensors

The wearable sensors have attracted a growing interest in different markets, including health, fitness, gaming, and entertainment, due to their outstanding characteristics of convenience, simplicity, accuracy, speed, and competitive price. The development of different types of wearable sensors was only possible due to advances in smart nanostructured materials with properties to detect changes in temperature, touch, pressure, movement, and humidity. Among the various sensing nanomaterials used in wearable sensors, the piezoresistive type has been extensively investigated and their potential have been demonstrated for different applications. In this review article, the current status and challenges of nanomaterials and fabrication processes for wearable piezoresistive sensors are presented in three parts. The first part focuses on the different types of sensing nanomaterials, namely, zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) piezoresistive nanomaterials. Then, in second part, their fabrication processes and integration are discussed. Finally, the last part presents examples of wearable piezoresistive sensors and their applications.

Laser-Assisted Fabrication of Injectable Nanofibrous Cell Carriers

The use of injectable biomaterials for cell delivery is a rapidly expanding field which may revolutionize the medical treatments by making them less invasive. However, creating desirable cell carriers poses significant challenges to the clinical implementation of cell-based therapeutics. At the same time, no method has been developed to produce injectable microscaffolds (MSs) from electrospun materials. Here the fabrication of injectable electrospun nanofibers is reported on, which retain their fibrous structure to mimic the extracellular matrix. The laser-assisted micro-scaffold fabrication has produced tens of thousands of MSs in a short time. An efficient attachment of cells to the surface and their proliferation is observed, creating cell-populated MSs. The cytocompatibility assays proved their biocompatibility, safety, and potential as cell carriers. Ex vivo results with the use of bone and cartilage tissues proved that NaOH hydrolyzed and chitosan functionalized MSs are compatible with living tissues and readily populated with cells. Injectability studies of MSs showed a high injectability rate, while at the same time, the force needed to eject the load is no higher than 25 N. In the future, the produced MSs may be studied more in-depth as cell carriers in minimally invasive cell therapies and 3D bioprinting applications.

Electrosprayed Nanoparticles as Drug Delivery systems for Biomedical Applications

BACKGROUND

Nanotechnology is a tool being used intensely in the area of drug delivery systems in the biomedical field. Electrospraying is one of the nanotechnological methods, which is growing due to its importance in the development of nanoparticles comprising bioactive compounds. It is helpful in improving the efficacy, reducing side effects of active drug elements, and is useful in targeted drug delivery. When compared to other conventional methods like nanoprecipitation, emulsion diffusion, and double emulsification, electrospraying offers better advantages to produce micro/nanoparticles due to its simplicity, cost-effectiveness, and single-step process.

OBJECTIVE

The aim of this paper is to highlight the use of electrosprayed nanoparticles for biomedical applications.

METHODS

We conducted a literature review on the usage of natural and synthetic materials to produce nanoparticles, which can be used as a drug delivery system for medical purposes.

RESULTS

We summarized a possible key role of electrosprayed nanoparticles in different therapeutic applications (tissue regeneration, cancer).

CONCLUSION

The modest literature production denotes that further investigation is needed to assess and validate the promising role of drug-loaded nanoparticles through the electrospraying process as noninvasive materials in the biomedical field.

Tissue engineering techniques for iPSC derived three-dimensional cardiac constructs

Recent developments in applied developmental physiology have provided well-defined methodologies for producing human stem cell derived cardiomyocytes. Cardiomyocytes produced in this way have become commonplace as cardiac physiology research models. This accessibility has also allowed for the development of tissue engineered human heart constructs for drug screening, surgical intervention, and investigating cardiac pathogenesis. However, cardiac tissue engineering is an interdisciplinary field that involves complex engineering and physiological concepts, which limits its accessibility. This review provides a readable, broad reaching, and thorough discussion of major factors to consider for the development of cardiovascular tissues from stem cell derived cardiomyocytes. This review will examine important considerations in undertaking a cardiovascular tissue engineering project, and will present, interpret, and summarize some of the recent advancements in this field. This includes reviewing different forms of tissue engineered constructs, a discussion on cardiomyocyte sources, and an in-depth discussion of the fabrication and maturation procedures for tissue engineered heart constructs.

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.

Electrohydrodynamic jet 3D printing in biomedical applications

Electrohydrodynamic Jet 3D Printing (e-jetting) is a promising technique developed from electrospinning, which enables precise fiber deposition in a layer-by-layer fashion with customized designs. Several studies have verified that e-jetted scaffolds were able to support cell attachment, proliferation, and extracellular matrix formation, as well as cell infiltration into the scaffold due to the well-defined pores. Besides, e-jetting has also been combined with other techniques to incorporate biomaterials (e.g., hydrogels and cell spheroids) that could not be e-jetted, to promote the biological performance of the scaffold. In the recent decade, applying e-jetting in the fabrication of tissue-engineered scaffolds has drawn a lot of interest. Moreover, efforts have been put to develop varied scaffolds for some specific biomedical applications such as cartilage, tendon, and blood vessel, which exhibited superior mechanical properties and promoted cell behaviors including cellular alignment and differentiation. This review article also provides the reader with some crucial considerations and major limitations of e-jetting, such as scaffold design, printability of large-scale constructs, applicable biomaterials, and cell behaviors. Overall, this review article expounds on perspectives in the context of development and biomedical applications of this technique. STATEMENT OF SIGNIFICANCE: E-jetting technique is able to produce fibers with diameter in micrometer scale, which has been considered as a promising 3D printing technique. This technique has shown promise for regeneration of tissue engineered scaffolds with well-defined structures, which has been reported to apply in regeneration of different tissue types. The superior controllability of the process endows the feasibility of constructing multi-scale scaffolds with great biological mimicry and cellular infiltration. The incorporation of other biomaterials into the e-jetted networks further reinforces the scope of applications as compared to e-jetted scaffolds only. There is no doubt that e-jetting will be a great tool for tissue engineered scaffolding, and this review article will give overall perspectives in this topic.

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.

Development of a modular, biocompatible thiolated gelatin microparticle platform for drug delivery and tissue engineering applications

The field of biomaterials has advanced significantly in the past decade. With the growing need for high-throughput manufacturing and screening, the need for modular materials that enable streamlined fabrication and analysis of tissue engineering and drug delivery schema has emerged. Microparticles are a powerful platform that have demonstrated promise in enabling these technologies without the need to modify a bulk scaffold. This building block paradigm of using microparticles within larger scaffolds to control cell ratios, growth factors and drug release holds promise. Gelatin microparticles (GMPs) are a well-established platform for cell, drug and growth factor delivery. One of the challenges in using GMPs though is the limited ability to modify the gelatin post-fabrication. In the present work, we hypothesized that by thiolating gelatin before microparticle formation, a versatile platform would be created that preserves the cytocompatibility of gelatin, while enabling post-fabrication modification. The thiols were not found to significantly impact the physicochemical properties of the microparticles. Moreover, the thiolated GMPs were demonstrated to be a biocompatible and robust platform for mesenchymal stem cell attachment. Additionally, the thiolated particles were able to be covalently modified with a maleimide-bearing fluorescent dye and a peptide, demonstrating their promise as a modular platform for tissue engineering and drug delivery applications.

Fabrication and Characterization of Cinnamaldehyde-Loaded Mesoporous Bioactive Glass Nanoparticles/PHBV-Based Microspheres for Preventing Bacterial Infection and Promoting Bone Tissue Regeneration

Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is considered a suitable polymer for drug delivery systems and bone tissue engineering due to its biocompatibility and biodegradability. However, the lack of bioactivity and antibacterial activity hinders its biomedical applications. In this study, mesoporous bioactive glass nanoparticles (MBGN) were incorporated into PHBV to enhance its bioactivity, while cinnamaldehyde (CIN) was loaded in MBGN to introduce antimicrobial activity. The blank (PHBV/MBGN) and the CIN-loaded microspheres (PHBV/MBGN/CIN5, PHBV/MBGN/CIN10, and PHBV/MBGN/CIN20) were fabricated by emulsion solvent extraction/evaporation method. The average particle size and zeta potential of all samples were investigated, as well as the morphology of all samples evaluated by scanning electron microscopy. PHBV/MBGN/CIN5, PHBV/MBGN/CIN10, and PHBV/MBGN/CIN20 significantly exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli in the first 3 h, while CIN releasing behavior was observed up to 7 d. Human osteosarcoma cell (MG-63) proliferation and attachment were noticed after 24 h cell culture, demonstrating no adverse effects due to the presence of microspheres. Additionally, the rapid formation of hydroxyapatite on the composite microspheres after immersion in simulated body fluid (SBF) during 7 d revealed the bioactivity of the composite microspheres. Our findings indicate that this system represents an alternative model for an antibacterial biomaterial for potential applications in bone tissue engineering.

Mechanistic understanding and potential application of electrospraying in food processing: a review

Electrospraying (ESPR) is a cost effective, flexible, and facile method that has been used in the pharmaceutical industry, and thanks to its wide variety of uses such as bioactive compound encapsulation, micronization, and food product coating, which have received a great attention in the food market. It uses a jet of polymer solution for processing food and food-derived products. Droplet size can be extremely small up to nanometers and can be regulated by altering applied voltage and flow rate. Compared to conventional techniques, it is simple, cost effective, uses less solvent and products are obtained in one step with a very high encapsulation efficiency (EE). Encapsulation provided using it protects bioactives from moisture, thermal, oxidative, and mechanical stresses, and thus provides them a good storage stability which will help in increasing the application of these ingredients in food formulation. This technique has an enormous potential for increasing the shelf life of fruit and vegetables through coating and improvement of eating quality. This study is aimed at overviewing the operating principles of ESPR, working parameters, applications, and advantages in the food sector. The article also covers new ESPR techniques like supercritical assisted ESPR and ESPR assisted by pressurized gas (EAPG) which have high yield as compared to conventional ESPR. This article is enriched with good information for research and development in ESPR techniques for development of novel foods.

Development of Polymer-Assisted Nanoparticles and Nanogels for Cancer Therapy: An Update

With cancer remaining as one of the main causes of deaths worldwide, many studies are undergoing the effort to look for a novel and potent anticancer drug. Nanoparticles (NPs) are one of the rising fields in research for anticancer drug development. One of the key advantages of using NPs for cancer therapy is its high flexibility for modification, hence additional properties can be added to the NPs in order to improve its anticancer action. Polymer has attracted considerable attention to be used as a material to enhance the bioactivity of the NPs. Nanogels, which are NPs cross-linked with hydrophilic polymer network have also exhibited benefits in anticancer application. The characteristics of these nanomaterials include non-toxic, environment-friendly, and variable physiochemical properties. Some other unique properties of polymers are also attributed by diverse methods of polymer synthesis. This then contributes to the unique properties of the nanodrugs. This review article provides an in-depth update on the development of polymer-assisted NPs and nanogels for cancer therapy. Topics such as the synthesis, usage, and properties of the nanomaterials are discussed along with their mechanisms and functions in anticancer application. The advantages and limitations are also discussed in this article.

Indwelling urinary catheter assembled with lidocaine-loaded polymeric strand for local sustained alleviation of bladder discomfort

Indwelling urinary catheters (IUCs) are used in clinical settings to assist detrusor contraction in hospitalized patients. However, an inserted IUC often causes catheter-related bladder discomfort. To resolve this, we propose an IUC coupled with local, sustained release of an anesthetic drug, lidocaine. For this, a thin strand composed of poly (lactic-co-glycolic acid) and lidocaine was separately prepared as a drug delivery carrier, which was then wound around the surface of the IUC to produce the drug-delivery IUC. Our results revealed that the drug-delivery IUC could exert the pain-relief effects for up to 7 days when placed in the bladder of living rats. Cystometrogram tests indicated that the drug-delivery IUC could significantly relieve bladder discomfort compared with the IUC without lidocaine. Furthermore, the expression of pain-related inflammatory markers, such as nerve growth factor, cyclooxygenase-2, and interleukin-6 in the biopsied bladder tissues was significantly lower when the drug-delivery IUC was used. Therefore, we conclude that an IUC simply assembled with a drug-loaded polymer strand can continuously release lidocaine to allow for the relief of bladder discomfort during the period of IUC insertion.

Electrosprayed mucoadhesive alginate-chitosan microcapsules for gastrointestinal delivery of probiotics

Besides viability protection, a sufficiently prolonged gastrointestinal retention of probiotics has emerged as critically important in improving the functional effectiveness of gastrointestinal delivery of these microorganisms. In this work, we formulated pure, resistant starch-reinforced and chitosan-coated alginate microparticles using an electrospray technique and evaluated their performance as mucoadhesive probiotic formulations for gastrointestinal delivery. In addition, we designed and successfully validated a novel experimental set-up of in vitro wash-off mucoadhesion test, using a portable and low-cost USB microscope for fluorescence imaging. In our test, pure chitosan microparticles (positive control) exhibited the greatest mucoadhesive property, whereas the alginate-resistant starch ones (negative control) were the least retentive on a gastric mucosa. These electrosprayed formulations were spherically shaped, with a size range of 30-600 µm (60-1300 µm with chitosan coating). Moreover, model probiotic Lactobacillus plantarum loaded in alginate-starch formulations was better protected against simulated gastric conditions than in alginate ones, but not better than in the chitosan-coated ones.

Barcode signal amplifying strategy for sensitive and accurate protein detection on LC-MS/MS

Protein drugs showing strong pharmaceutical activity, high specificity, and low toxicity and side effects have drawn extensive attention in the field of life sciences and medicine. Precise evaluation of the function of these drugs requires accurate and sensitive detection methods. Here, we report a novel chromatography-tandem mass spectrometry (LC-MS/MS) method for sensitive and selective detection of protein drugs. Magnetic nanoparticles (Apt29@MNPs) were functionalized by thrombin aptamers, and quantum dots (Apt15@ss@QDs) were dual-functionalized with quantitative thrombin aptamers and small molecules with high ionization efficiency as the mass barcode. After Apt29@MNPs specifically purify and enrich thrombin from biological samples, they can form a nano "sandwich structure" when Apt15@ss@QDs are added, resulting in the release of the mass barcode for LC-MS/MS analysis via the cutting of the disulfide bond. Since there is a higher quantitative molecular ratio of mass barcode to thrombin in the nano-"sandwich structure", quantitative detection of thrombin with high sensitivity and selectivity can be achieved via the LC-MS/MS detection of the mass barcode with high ionization efficiency rather than thrombin, which effectively avoids the disadvantages of direct protein detection by mass spectrometry. The established method for thrombin detection shows a good linear relationship in a concentration range of 0.00115-1.15 nM with a limit of detection (LOD) of 0.0007 nM. The present work provides a new approach for the effective and sensitive quantitative analysis of protein drugs and would be of great significance in promoting the development of protein drugs and clinical applications.

Fabrication of a Greener TiO2@Gum Arabic-Carbon Paste Electrode for the Electrochemical Detection of Pb2+ Ions in Plastic Toys

A novel greener methodology is reported for the synthesis of titanium dioxide (TiO2) nanoparticles (NPs) using gum Arabic (Acacia senegal) and the characterization of the ensuing TiO2 NPs by various techniques such as X-ray diffraction (XRD), Fourier transform infrared, Raman spectroscopy, scanning electron microscopy-energy dispersive X-ray, transmission electron microscopy (TEM), high resolution-TEM, and UV-visible spectroscopy. The XRD analysis confirmed the formation of TiO2 NPs in the anatase phase with high crystal purity, while TEM confirmed the size to be 8.9 ± 1.5 nm with a spherical morphology. The electrode for the electrochemical detection of Pb2+ ions was modified by a carbon paste fabricated using the synthesized TiO2 NPs. Compared to the bare electrode, the fabricated electrode exhibited improved electro-catalytic activity toward the reduction of Pb2+ ions. The detection limit, quantification limit, and the sensitivity of the developed electrode were observed by using differential pulse voltammetry to be 506 ppb, 1.68 ppm, and 0.52 ± 0.01 μA μM-1, respectively. The constructed electrode was tested for the detection of lead content in plastic toys.

Electrospun fibers based on carbohydrate gum polymers and their multifaceted applications

Electrospinning has garnered significant attention in view of its many advantages such as feasibility for various polymers, scalability required for mass production, and ease of processing. Extensive studies have been devoted to the use of electrospinning to fabricate various electrospun nanofibers derived from carbohydrate gum polymers in combination with synthetic polymers and/or additives of inorganic or organic materials with gums. In view of the versatility and the widespread choice of precursors that can be deployed for electrospinning, various gums from both, the plants and microbial-based gum carbohydrates are holistically and/or partially included in the electrospinning solution for the preparation of functional composite nanofibers. Moreover, our strategy encompasses a combination of natural gums with other polymers/inorganic or nanoparticles to ensue distinct properties. This early established milestone in functional carbohydrate gum polymer-based composite nanofibers may be deployed by specialized researchers in the field of nanoscience and technology, and especially for exploiting electrospinning of natural gums composites for diverse applications.

Combination of electrospinning with other techniques for the fabrication of 3D polymeric and composite nanofibrous scaffolds with improved cellular interactions

The development of three-dimensional (3D) scaffolds with physical and chemical topological cues at the macro-, micro-, and nanometer scale is urgently needed for successful tissue engineering applications. 3D scaffolds can be manufactured by a wide variety of techniques. Electrospinning technology has emerged as a powerful manufacturing technique to produce non-woven nanofibrous scaffolds with very interesting features for tissue engineering products. However, electrospun scaffolds have some inherent limitations that compromise the regeneration of thick and complex tissues. By integrating electrospinning and other fabrication technologies, multifunctional 3D fibrous assemblies with micro/nanotopographical features can be created. The proper combination of techniques leads to materials with nano and macro-structure, allowing an improvement in the biological performance of tissue-engineered constructs. In this review, we focus on the most relevant strategies to produce electrospun polymer/composite scaffolds with 3D architecture. A detailed description of procedures involving physical and chemical agents to create structures with large pores and 3D fiber assemblies is introduced. Finally, characterization and biological assays including in vitro and in vivo studies of structures intended for the regeneration of functional tissues are briefly presented and discussed.

Development of an antimicrobial peptide-loaded mineralized collagen bone scaffold for infective bone defect repair

The repair of infective bone defects is a great challenge in clinical work. It is of vital importance to develop a kind of bone scaffold with good osteogenic properties and long-term antibacterial activity for local anti-infection and bone regeneration. A porous mineralized collagen (MC) scaffold containing poly(d,l-lactide-co-glycolic acid) (PLGA) microspheres loaded with two antibacterial synthetic peptides, Pac-525 or KSL-W was developed and characterized via scanning electron microscopy (SEM), porosity measurement, swelling and mechanical tests. The results showed that the MC scaffold embedded with smooth and compact PLGA microspheres had a positive effect on cell growth and also had antibacterial properties. Through toxicity analysis, cell morphology and proliferation analysis and alkaline phosphatase evaluation, the antibacterial scaffolds showed excellent biocompatibility and osteogenic activity. The antibacterial property evaluated with Staphylococcus aureus and Escherichia coli suggested that the sustained release of Pac-525 or KSL-W from the scaffolds could inhibit the bacterial growth aforementioned in the long term. Our results suggest that the antimicrobial peptides-loaded MC bone scaffold has good antibacterial and osteogenic activities, thus providing a great promise for the treatment of infective bone defects.

Poultry Shelf-Life Enhancing Potential of Nanofibers and Nanoparticles Containing Porphyra dioica Extracts

Aqueous extracts of commercially available red macroalgae Porphyra dioica were integrated as inner coatings of food-grade polypropylene (PP) films through use of electrospinning and electrospraying technologies. Two coating formulations (A = 5 wt% P. dioica extract and 7.5 wt% polyvinyl alcohol (PVA); B = 1 wt% P. dioica extract, 1 wt% PVA, and 17% gelatine) were evaluated as to their capacity to delay spoilage of minced chicken breasts, through monitoring of microbial growth (total mesophile aerobic colony counts), colour stability, lipid oxidation (thiobarbituric acid reactive substances (TBARS)), and sensory analysis over a 4-day refrigerated storage. Scanning electron microscopy (SEM) imaging revealed an increased nanofiber and nanoparticle density on extract-enriched fibers, without compromise to their morphology or the homogeneity of the coatings. Total microbial counts on coating B samples was significantly (p < 0.001) reduced compared to uncoated plastic wraps. The coated samples also exhibited fewer colour degradation, though the coatings did not differ substantially from uncoated plastic wrap. Sensory analysis test subjects successfully distinguished the raw samples based on their treatment and gave a positive approval rating (66.7%) to the extract-enriched coatings when asked about edibility post storage.