Stem cell-extracellular vesicles as drug delivery systems: New frontiers for silk/curcumin nanoparticles

The Emerging Role of Human Gut Bacteria Extracellular Vesicles in Mental Disorders and Developing New Pharmaceuticals

In recent years, further evidence has emerged regarding the involvement of extracellular vesicles in various human physiopathological conditions such as Alzheimer's disease, Parkinson's disease, irritable bowel syndrome, and mental disorders. The biogenesis and cargo of such vesicles may reveal their impact on human health nd disease and set the underpinnings for the development of novel chemical compounds and pharmaceuticals. In this review, we examine the link between bacteria-derived exosomes in the gastrointestinal tract and mental disorders, such as depression and anxiety disorders. Crucially, we focus on whether changes in the gut environment affect the human mental state or the other way around. Furthermore, the possibility of handling bacteria-derived exosomes as vectors of chemicals to treat such conditions is examined.

Recent advances of silk fibroin materials: From molecular modification and matrix enhancement to possible encapsulation-related functional food applications

Silk fibroin materials are emergingly explored for food applications due to their inherent properties including safe oral consumption, biocompatibility, gelatinization, antioxidant performance, and mechanical properties. However, silk fibroin possesses drawbacks like brittleness owing to its inherent specific composition and structure, which limit their applications in this field. This review discusses current progress about molecular modification methods on silk fibroin such as extraction, blending, self-assembly, enzymatic catalysis, etc., to address these limitations and improve their physical/chemical properties. It also summarizes matrix enhancement strategies including freeze drying, spray drying, electrospinning/electrospraying, microfluidic spinning/wheel spinning, desolvation and supercritical fluid, to generate nano-, submicron-, micron-, or bulk-scale materials. It finally highlights the food applications of silk fibroin materials, including nutraceutical improvement, emulsions, enzyme immobilization and 3D/4D printing. This review also provides insights on potential opportunities (like safe modification, toxicity risk evaluation, and digestion conditions) and possibilities (like digital additive manufacturing) in functional food industry.

An Up-to-date Review on Protein-based Nanocarriers in the Management of Cancer

BACKGROUND

A big health issue facing the world's population is cancer. An alarming increase in cancer patients was anticipated by worldwide demographic statistics, which showed that the number of patients with different malignancies was rapidly increasing. By 2025, probably 420 million cases were projected to be achieved. The most common cancers diagnosed are breast, colorectal, prostate, and lung. Conventional treatments, such as surgery, chemotherapy, and radiation therapy, have been practiced.

OBJECTIVE

In recent years, the area of cancer therapy has changed dramatically with expanded studies on the molecular-level detection and treatment of cancer. Recent advances in cancer research have seen significant advances in therapies such as chemotherapy and immunotherapy, although both have limitations in effectiveness and toxicity.

METHODS

The development of nanotechnology for anticancer drug delivery has developed several potentials as nanocarriers, which may boost the pharmacokinetic and pharmacodynamic effects of the drug product and substantially reduce the side effects.

RESULTS

The advancement in non-viral to viral-based protein-based nanocarriers for treating cancer has earned further recognition in this respect. Many scientific breakthroughs have relied on protein-based nanocarriers, and proteins are essential organic macromolecules for life. It allows targeted delivery of passive or active tumors using non-viral-based protein-based nanocarriers to viral-based protein nanocarriers. When targeting cancer cells, both animal and plant proteins may be used in a formulation process to create self-assembled viruses and platforms that can successfully eradicate metastatic cancer cells.

CONCLUSION

This review, therefore, explores in depth the applications of non-viral to viral proteinbased noncarriers with a specific focus on intracellular drug delivery and anti-cancer drug targeting ability.

State-of-the-art advances in nanocomposite and bio-nanocomposite polymeric materials: A comprehensive review

The modern eco-friendly materials used in research and innovation today consist of nanocomposites and bio-nanocomposite polymers. Their unique composite properties make them suitable for various industrial, medicinal, and energy applications. Bio-nanocomposite polymers are made of biopolymer matrices that have nanofillers dispersed throughout them. There are several types of fillers that can be added to polymers to enhance their quality, such as cellulose-based fillers, clay nanomaterials, carbon black, talc, carbon quantum dots, and many others. Biopolymer-based nanocomposites are considered a superior alternative to traditional materials as they reduce reliance on fossil fuels and promote the use of renewable resources. This review covers the current state-of-the-art in nanocomposite and bio-nanocomposite materials, focusing on ways to improve their features and the various applications they can be used for. The review article also investigates the utilization of diverse nanocomposites as a viable approach for developing bio-nanocomposites. It delves into the underlying principles that govern the synthesis of these materials and explores their prospective applications in the biomedical field, food packaging, sensing (Immunosensors), and energy storage devices. Lastly, the review discusses the future outlook and current challenges of these materials, with a focus on sustainability.

Recent developments in natural biopolymer based drug delivery systems

Targeted delivery of drug molecules to diseased sites is a great challenge in pharmaceutical and biomedical sciences. Fabrication of drug delivery systems (DDS) to target and/or diagnose sick cells is an effective means to achieve good therapeutic results along with a minimal toxicological impact on healthy cells. Biopolymers are becoming an important class of materials owing to their biodegradability, good compatibility, non-toxicity, non-immunogenicity, and long blood circulation time and high drug loading ratio for both macros as well as micro-sized drug molecules. This review summarizes the recent trends in biopolymer-based DDS, forecasting their broad future clinical applications. Cellulose chitosan, starch, silk fibroins, collagen, albumin, gelatin, alginate, agar, proteins and peptides have shown potential applications in DDS. A range of synthetic techniques have been reported to design the DDS and are discussed in the current study which is being successfully employed in ocular, dental, transdermal and intranasal delivery systems. Different formulations of DDS are also overviewed in this review article along with synthesis techniques employed for designing the DDS. The possibility of these biopolymer applications points to a new route for creating unique DDS with enhanced therapeutic qualities for scaling up creative formulations up to the clinical level.

Optimized silk fibroin nanoparticle functionalization with anti-CEA nanobody enhancing active targeting of colorectal cancer cells

This work aimed to establish a simple and feasible method to obtain silk fibroin nanoparticles (SFNPs) with uniform particles size, and then modify the SFNPs with nanobody (Nb) 11C12 targeting the proximal membrane end of carcinoembryonic antigen on the surface of colorectal cancer (CRC) cells. The regenerated silk fibroin (SF) was isolated using ultrafiltration tubes with a 50 kDa molecular weight cut-off, and the retention fraction (named as SF > 50 kDa) was further self-assembled into SFNPs by ethanol induction. Scanning electron microscope (SEM) and high-resolution transmission electron microscop showed that the SFNPs with uniform particles size were formed. Due to electrostatic adsorption and pH responsiveness, SFNPs have been proved to effectively load and release the anticancer drug doxorubicin hydrochloride (DOX) (DOX@SFNPs). Further, targeting molecule Nb 11C12 was used to modify these nanoparticles, constituting the targeted outer layer of the drug delivery system (DOX@SFNPs-11C12), achieving precise localization to cancer cells. The release amount of DOX observed fromin vitrodrug release profiles increased as follows: pH 7.4 < pH 6.8 < pH 5.4, demonstrating that the DOX release could be accelerated in a weakly acidic environment.In vitrocytotoxicity experiments displayed that SFNPs-11C12 nanoparticles exhibited good safety and biocompatibility. Drug-loaded nanoparticles, DOX@SFNPs-11C12, led to higher LoVo cells apoptosis compared to DOX@SFNPs. Fluorescence spectrophotometer characterization and confocal laser scanning microscopy further showed that the internalization of DOX was highest in the DOX@SFNPs-11C12, certifying that the introduced targeting molecule enhanced the uptake of drug delivery system by LoVo cells. This study provides a simple and operational approach to developing an optimized SFNPs drug delivery system modified by targeting Nb, which can be a good candidate for CRC therapy.

Advanced treatment strategies in breast cancer: A comprehensive mechanistic review

Breast cancer is a destructive lump type that affects women globally. Despite the availability of multi-directional therapeutic strategies, advanced stages of breast cancer are difficult to treat and impose major healthcare burdens. This situation reinforces the need to identify new potential therapeutic compounds with better clinical features. In this context, different treatment methods were included such as Endocrine therapy, chemotherapy, Radiation therapy, antimicrobial peptide-dependent growth inhibitor, liposome-based drug delivery, antibiotics used as a co-medication, photothermal, immunotherapy, and nano drug delivery systems such as Bombyx mori natural protein sericin and its mediated nanoparticles are promising biomedical agents. They have been tested as an anticancer agent against various malignancies in pre-clinical settings. The biocompatible and restricted breakdown properties of silk sericin and sericin-conjugated nanoparticles made them perfect contenders for a nanoscale drug-delivery system.

cRGD-Functionalized Silk Fibroin Nanoparticles: A Strategy for Cancer Treatment with a Potent Unselective Naphthalene Diimide Derivative

Developing drug delivery systems to target cytotoxic drugs directly into tumor cells is still a compelling need with regard to reducing side effects and improving the efficacy of cancer chemotherapy. In this work, silk fibroin nanoparticles (SFNs) have been designed to load a previously described cytotoxic compound (NDI-1) that disrupts the cell cycle by specifically interacting with non-canonical secondary structures of DNA. SFNs were then functionalized on their surface with cyclic pentapeptides incorporating the Arg-Gly-Asp sequence (cRGDs) to provide active targeting toward glioma cell lines that abundantly express ανβ3 and ανβ5 integrin receptors. Cytotoxicity and selective targeting were assessed by in vitro tests on human glioma cell lines U373 (highly-expressing integrin subunits) and D384 cell lines (low-expressing integrin subunits in comparison to U373). SFNs were of nanometric size (d50 less than 100 nm), round shaped with a smooth surface, and with a negative surface charge; overall, these characteristics made them very likely to be taken up by cells. The active NDI-1 was loaded into SFNs with high encapsulation efficiency and was not released before the internalization and degradation by cells. Functionalization with cRGDs provided selectivity in cell uptake and thus cytotoxicity, with a significantly higher cytotoxic effect of NDI-1 delivered by cRGD-SFNs on U373 cells than on D384 cells. This manuscript provides an in vitro proof-of-concept of cRGD-silk fibroin nanoparticles’ active site-specific targeting of tumors, paving the way for further in vivo efficacy tests.

Bioengineered extracellular vesicles: future of precision medicine for sepsis

Sepsis is a syndromic response to infection and is frequently a final common pathway to death from many infectious diseases worldwide. The complexity and high heterogeneity of sepsis hinder the possibility to treat all patients with the same protocol, requiring personalized management. The versatility of extracellular vesicles (EVs) and their contribution to sepsis progression bring along promises for one-to-one tailoring sepsis treatment and diagnosis. In this article, we critically review the endogenous role of EVs in sepsis progression and how current advancements have improved EVs-based therapies toward their translational future clinical application, with innovative strategies to enhance EVs effect. More complex approaches, including hybrid and fully synthetic nanocarriers that mimic EVs, are also discussed. Several pre-clinical and clinical studies are examined through the review to offer a general outlook of the current and future perspectives of EV-based sepsis diagnosis and treatment.

Role of curcumin and its nanoformulations in the treatment of neurological diseases through the effects on stem cells

Curcumin from turmeric is a natural phenolic compound with a promising potential to regulate fundamental processes involved in neurological diseases, including inflammation, oxidative stress, protein aggregation, and apoptosis at the molecular level. In this regard, employing nanoformulation can improve curcumin efficiency by reducing its limitations, such as low bioavailability. Besides curcumin, growing data suggest that stem cells are a noteworthy candidate for neurodegenerative disorders therapy due to their anti-inflammatory, anti-oxidative, and neuronal-differentiation properties, which result in neuroprotection. Curcumin and stem cells have similar neurogenic features and can be co-administered in a cell-drug delivery system to achieve better combination therapeutic outcomes for neurological diseases. Based on the evidence, curcumin can induce the neuroprotective activity of stem cells by modulating their related signalling pathways. The present review is about the role of curcumin and its nanoformulations in the improvement of neurological diseases alone and through the effect on different categories of stem cells by discussing the underlying mechanisms to provide a roadmap for future investigations.

Scalable Production of Monodisperse Bioactive Spider Silk Nanowires

Elongated protein-based micro- and nanostructures are of great interest for a wide range of biomedical applications, where they can serve as a backbone for surface functionalization and as vehicles for drug delivery. Current production methods for protein constructs lack precise control of either shape and dimensions or render structures fixed to substrates. This work demonstrates production of recombinant spider silk nanowires suspended in solution, starting with liquid bridge induced assembly (LBIA) on a substrate, followed by release using ultrasonication, and concentration by centrifugation. The significance of this method lies in that it provides i) reproducability (standard deviation of length <13% and of diameter <38%), ii) scalability of fabrication, iii) compatibility with autoclavation with retained shape and function, iv) retention of bioactivity, and v) easy functionalization both pre- and post-formation. This work demonstrates how altering the function and nanotopography of a surface by nanowire coating supports the attachment and growth of human mesenchymal stem cells (hMSCs). Cell compatibility is further studied through integration of nanowires during aggregate formation of hMSCs and the breast cancer cell line MCF7. The herein-presented industrial-compatible process enables silk nanowires for use as functionalizing agents in a variety of cell culture applications and medical research.

Trojan-horse silk fibroin nanocarriers loaded with a re-call antigen to redirect immunity against cancer

BACKGROUND

The current challenge for immunotherapies is to generate effective antitumor immunity. Since tumor immune escape mechanisms do not impact pre-existing and consolidated immune responses, we tested the hypothesis of redirecting a pregenerated immunity to cancer: to recall a non-tumor antigen response against the tumor, silk fibroin nanoparticles (SFNs) have been selected as 'Trojan-horse' carriers, promoting the antigen uptake by the tumor cells.

METHODS

SFNs have been loaded with either ovalbumin (OVA) or CpG oligonucleotide (CpG) as antigen or adjuvant, respectively. In vitro uptake of SFNs by tumor (B16/F10 melanoma and MB49 bladder cancer) or dendritic cells, as well as the presence of OVA-specific T cells in splenic and tumor-infiltrating lymphocytes, were assessed by cytometric analyses. Proof-of-concept of in vivo efficacy was achieved in an OVA-hyperimmune B16/F10 murine melanoma model: SFNs-OVA or SFNs-CpG were injected, separately or in association, into the subcutaneous peritumoral area. Cancer dimensions/survival time were monitored, while, at the molecular level, system biology approaches based on graph theory and experimental proteomic data were performed.

RESULTS

SFNs were efficiently in vitro uptaken by cancer and dendritic cells. In vivo peritumor administration of SFNs-OVA redirected OVA-specific cytotoxic T cells intratumorally. Proteomics and systems biology showed that peritumoral treatment with either SFNs-OVA or SFNs-CpG dramatically modified tumor microenvironment with respect to the control (CTR), mainly involving functional modules and hubs related to angiogenesis, inflammatory mediators, immune function, T complex and serpins expression, redox homeostasis, and energetic metabolism. Both SFNs-OVA and SFNs-CpG significantly delayed melanoma growth/survival time, and their effect was additive.

CONCLUSIONS

Both SFNs-OVA and SFNs-CpG induce effective anticancer response through complementary mechanisms and show the efficacy of an innovative active immunotherapy approach based on the redirection of pre-existing immunity against cancer cells. This approach could be universally applied for solid cancer treatments if translated into the clinic using re-call antigens of childhood vaccination.

Equine Muscle Derived Mesenchymal Stem Cells Loaded with Water-Soluble Curcumin: Modulation of Neutrophil Activation and Enhanced Protection against Intracellular Oxidative Attack

We investigated the antioxidant potential of equine mesenchymal stem cells derived from muscle microbiopsies (mdMSCs), loaded by a water-soluble curcumin lysinate incorporated into hydroxypropyl-β-cyclodextrin (NDS27). The cell loading was rapid and dependent on NDS27 dosage (14, 7, 3.5 and 1 µM). The immunomodulatory capacity of loaded mdMSCs was evaluated by ROS production, on active and total myeloperoxidase (MPO) degranulation and neutrophil extracellular trap (NET) formation after neutrophil stimulation. The intracellular protection of loaded cells was tested by an oxidative stress induced by cumene hydroperoxide. Results showed that 10 min of mdMSC loading with NDS27 did not affect their viability while reducing their metabolism. NDS27 loaded cells in presence of 14, 7 µM NDS27 inhibited more intensively the ROS production, the activity of the MPO released and bound to the NET after neutrophil stimulation. Furthermore, loaded cells powerfully inhibited intracellular ROS production induced by cumene as compared to control cells or cyclodextrin-loaded cells. Our results showed that the loading of mdMSCs with NDS27 significantly improved their antioxidant potential against the oxidative burst of neutrophil and protected them against intracellular ROS production. The improved antioxidant protective capacity of loaded mdMSCs could be applied to target inflammatory foci involving neutrophils.

Emerging Bioactive Agent Delivery-Based Regenerative Therapies for Lower Genitourinary Tissues

Injury to lower genitourinary (GU) tissues, which may result in either infertility and/or organ dysfunctions, threatens the overall health of humans. Bioactive agent-based regenerative therapy is a promising therapeutic method. However, strategies for spatiotemporal delivery of bioactive agents with optimal stability, activity, and tunable delivery for effective sustained disease management are still in need and present challenges. In this review, we present the advancements of the pivotal components in delivery systems, including biomedical innovations, system fabrication methods, and loading strategies, which may improve the performance of delivery systems for better regenerative effects. We also review the most recent developments in the application of these technologies, and the potential for delivery-based regenerative therapies to treat lower GU injuries. Recent progress suggests that the use of advanced strategies have not only made it possible to develop better and more diverse functionalities, but also more precise, and smarter bioactive agent delivery systems for regenerative therapy. Their application in lower GU injury treatment has achieved certain effects in both patients with lower genitourinary injuries and/or in model animals. The continuous evolution of biomaterials and therapeutic agents, advances in three-dimensional printing, as well as emerging techniques all show a promising future for the treatment of lower GU-related disorders and dysfunctions.

Enhancement strategies for mesenchymal stem cells and related therapies

Cell therapy, particularly mesenchymal stem/stromal (MSC) therapy, has been investigated for a wide variety of disease indications, particularly those with inflammatory pathologies. However, recently it has become evident that the MSC is far from a panacea. In this review we will look at current and future strategies that might overcome limitations in efficacy. Many of these take their inspiration from stem cell niche and the mechanism of MSC action in response to the injury microenvironment, or from previous gene therapy work which can now benefit from the added longevity and targeting ability of a live cell vector. We will also explore the nascent field of extracellular vesicle therapy and how we are already seeing enhancement protocols for this exciting new drug. These enhanced MSCs will lead the way in more difficult to treat diseases and restore potency where donors or manufacturing practicalities lead to diminished MSC effect.

Effects of Cell Density and Microenvironment on Stem Cell Mitochondria Transfer among Human Adipose-Derived Stem Cells and HEK293 Tumorigenic Cells

Stem cells (SC) are largely known for their potential to restore damaged tissue through various known mechanisms. Among these mechanisms is their ability to transfer healthy mitochondria to injured cells to rescue them. This mitochondrial transfer plays a critical role in the healing process. To determine the optimal parameters for inducing mitochondrial transfer between cells, we assessed mitochondrial transfer as a function of seeding density and in two-dimensional (2D) and semi three-dimensional (2.5D) culture models. Since mitochondrial transfer can occur through direct contact or secretion, the 2.5D culture model utilizes collagen to provide cells with a more physiologically relevant extracellular matrix and offers a more realistic representation of cell attachment and movement. Results demonstrate the dependence of mitochondrial transfer on cell density and the distance between donor and recipient cell. Furthermore, the differences found between the transfer of mitochondria in 2D and 2.5D microenvironments suggest an optimal mode of mitochondria transport. Using these parameters, we explored the effects on mitochondrial transfer between SCs and tumorigenic cells. HEK293 (HEK) is an immortalized cell line derived from human embryonic kidney cells which grow rapidly and form tumors in culture. Consequently, HEKs have been deemed tumorigenic and are widely used in cancer research. We observed mitochondrial transfer from SCs to HEK cells at significantly higher transfer rates when compared to a SC–SC co-culture system. Interestingly, our results also revealed an increase in the migratory ability of HEK cells when cultured with SCs. As more researchers find co-localization of stem cells and tumors in the human body, these results could be used to better understand their biological relationship and lead to enhanced therapeutic applications.

Nanoparticles as an effective drug delivery system in COVID-19

Background

The global healthcare sector has been dealing with a situation known as a novel severe acute respiratory syndrome (SARS-CoV-2) since the end of 2019. Covid-19 is an acronym for Covid-19 (Coronavirus Disease- 2019). It causes a respiratory infection that includes cold, sneezing and coughing, and pneumonia. In the case of an animal, it causes diarrhea and upper respiratory diseases. Covid-19 transmitted human to human via airborne droplets. First Covid-19 emerged in Wuhan market China and it spread rapidly throughout the World. As we know nanoparticles are a novel drug delivery system. They have various advantageous effects like increasing the efficacy of the drug, safety, etc. In this review, we study about the nanoparticles and summarize how it is effective during drug delivery system in Covid-19. Chitosan is a much focused biopolymeric nanoparticle. It delivers drugs to the specific target site. In a recent health crisis, chitosan nanoparticles are one of the ways to release drugs of Covid-19, and specifically in the lungs of the affected patients. We studied and extracted our data from various research papers, review papers, and some other articles.

Objective

The main goal is to study the nanoparticles and their future aspects which is an effective drug delivery system in Covid-19.

Methods

The bibliographic search was done through a systematic search. The terms “Nanoparticles”, “Covid-19 ”, “Drug delivery” etc. were used to search the databases/search engines like “Google Scholar”, “NCBI”, “PubMed”, “Science Direct” etc. These databases and search engines used here perform the limited criteria of search to conduct a systematic literature survey for the study and report writing. All the text from the articles and research papers were studied and analyzed. The various articles and research papers were used in writing this report and all of which are mentioned in the reference section of this report.

Conclusion

Our current studies reveal that nanoparticles may prove very helpful in the delivery of drugs for Covid-19 treatment. Many cases showed that patients, where drugs are delivered with the help of nanoparticles, produced very few side effects.

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.

Biomaterials for Soft Tissue Repair and Regeneration: A Focus on Italian Research in the Field

Tissue repair and regeneration is an interdisciplinary field focusing on developing bioactive substitutes aimed at restoring pristine functions of damaged, diseased tissues. Biomaterials, intended as those materials compatible with living tissues after in vivo administration, play a pivotal role in this area and they have been successfully studied and developed for several years. Namely, the researches focus on improving bio-inert biomaterials that well integrate in living tissues with no or minimal tissue response, or bioactive materials that influence biological response, stimulating new tissue re-growth. This review aims to gather and introduce, in the context of Italian scientific community, cutting-edge advancements in biomaterial science applied to tissue repair and regeneration. After introducing tissue repair and regeneration, the review focuses on biodegradable and biocompatible biomaterials such as collagen, polysaccharides, silk proteins, polyesters and their derivatives, characterized by the most promising outputs in biomedical science. Attention is pointed out also to those biomaterials exerting peculiar activities, e.g., antibacterial. The regulatory frame applied to pre-clinical and early clinical studies is also outlined by distinguishing between Advanced Therapy Medicinal Products and Medical Devices.

Changes in Amino Acid Profiles and Bioactive Compounds of Thai Silk Cocoons as Affected by Water Extraction

Silk proteins have many advantageous components including proteins and pigments. The proteins-sericin and fibroin-have been widely studied for medical applications due to their good physiochemical properties and biological activities. Various strains of cocoon display different compositions such as amino-acid profiles and levels of antioxidant activity. Therefore, the objectives of this study were to find a suitable silk protein extraction method to obtain products with chemical and biological properties suitable as functional foods in two strains of Bombyx mori silk cocoon (Nangsew strains; yellow cocoon) and Samia ricini silk cocoon (Eri strains; white cocoon) extracted by water at 100 °C for 2, 4, 6 and 8 h. The results showed that Nangsew strains extracted for 6 h contained the highest amounts of protein, amino acids, total phenolics (TPC) and total flavonoids (TFC), plus DPPH radical-scavenging activity, ABTS radical scavenging capacity, and ferric reducing antioxidant power (FRAP), anti-glycation, α-amylase and α-glucosidase inhibition. The longer extraction time produced higher concentrations of amino acids, contributing to sweet and umami tastes in both silk strains. It seemed that the bitterness decreased as the extraction time increased, resulting in improvements in the sweetness and umami of silk-protein extracts.

Silk Fibroin Nanoparticle Functionalization with Arg-Gly-Asp Cyclopentapeptide Promotes Active Targeting for Tumor Site-Specific Delivery

Simple Summary

Many tumor cell types overexpress integrins, a glycoprotein, on their cell membranes. The tripeptide motif Arg-Gly-Asp (RGD) is well-known for being recognized by the integrin superfamily members and can thus be used to actively target nanoparticles containing cytotoxic drugs directly to the tumor cells. According to this strategy, the antitumor activity is boosted, and healthy organs are spared. In this paper, silk fibroin, a naturally derived protein, has been used to prepare nanoparticles (SFNs) functionalized on their surface with RGD. In vitro experiments revealed that functionalization of SFNs with RGD provided active internalization by tumor cells overexpressing integrin receptors. Therefore, RGD-SFNs may be used for tumor-specific delivery of anticancer drugs.

Abstract

Arg-Gly-Asp (RGD)-based cyclopentapeptides (cRGDs) have a high affinity towards integrin αvβ3 and αvβ5, which are overexpressed by many tumor cells. Here, curcumin-loaded silk fibroin nanoparticles (SFNs) have been functionalized on the surface with cRGD to provide active targeting towards tumor cells; a “click reaction” between the RGD-based cyclopentapeptide carrying an azide group and triple-bond-functionalized nanoparticles has been exploited. Both naked and functionalized SFNs were less than 200 nm in diameter and showed a round-shaped morphology but, after functionalization, SFNs increased in size and protein molecular weight. The functionalization of SFNs’ surfaces with cRGD provided active internalization by cells overexpressing integrin receptors. At the lowest concentration tested (0.01 mg/mL), functionalized SFNs showed more effective uptake with respect to the naked by tumor cells that overexpress integrin receptors (but not for non-overexpressing ones). In contrast, at higher concentrations, the non-specific cell membrane protein–particle interactions are promoted and coupled to specific and target mediated uptake. Visual observations by fluorescence microscopy suggested that SFNs bind to integrin receptors on the cell surface and are then internalized by endocytosis. Overall, SFN functionalization provided in vitro active targeting for site-specific delivery of anticancer drugs, boosting activity and sparing healthy organs.

Overview and Update on Methods for Cargo Loading into Extracellular Vesicles

The enormous library of pharmaceutical compounds presents endless research avenues. However, several factors limit the therapeutic potential of these drugs, such as drug resistance, stability, off-target toxicity, and inadequate delivery to the site of action. Extracellular vesicles (EVs) are lipid bilayer-delimited particles and are naturally released from cells. Growing evidence shows that EVs have great potential to serve as effective drug carriers. Since EVs can not only transfer biological information, but also effectively deliver hydrophobic drugs into cells, the application of EVs as a novel drug delivery system has attracted considerable scientific interest. Recently, EVs loaded with siRNA, miRNA, mRNA, CRISPR/Cas9, proteins, or therapeutic drugs show improved delivery efficiency and drug effect. In this review, we summarize the methods used for the cargo loading into EVs, including siRNA, miRNA, mRNA, CRISPR/Cas9, proteins, and therapeutic drugs. Furthermore, we also include the recent advance in engineered EVs for drug delivery. Finally, both advantages and challenges of EVs as a new drug delivery system are discussed. Here, we encourage researchers to further develop convenient and reliable loading methods for the potential clinical applications of EVs as drug carriers in the future.

The Use of Alternative Strategies for Enhanced Nanoparticle Delivery to Solid Tumors

Nanomaterial (NM) delivery to solid tumors has been the focus of intense research for over a decade. Classically, scientists have tried to improve NM delivery by employing passive or active targeting strategies, making use of the so-called enhanced permeability and retention (EPR) effect. This phenomenon is made possible due to the leaky tumor vasculature through which NMs can leave the bloodstream, traverse through the gaps in the endothelial lining of the vessels, and enter the tumor. Recent studies have shown that despite many efforts to employ the EPR effect, this process remains very poor. Furthermore, the role of the EPR effect has been called into question, where it has been suggested that NMs enter the tumor via active mechanisms and not through the endothelial gaps. In this review, we provide a short overview of the EPR and mechanisms to enhance it, after which we focus on alternative delivery strategies that do not solely rely on EPR in itself but can offer interesting pharmacological, physical, and biological solutions for enhanced delivery. We discuss the strengths and shortcomings of these different strategies and suggest combinatorial approaches as the ideal path forward.

Curcumin Loaded and Co-loaded Nanosystems: A Review from a Biological Activity Enhancement Perspective

BACKGROUND

Curcumin is a natural phenolic compound exhibiting multiple bioactivities that have been evaluated in vitro, in vivo as well as through clinical studies in humans. Some of them include antimicrobial, antioxidant, anti-inflammatory, and central nervous system protective effects. Further, curcumin is generally recognized as a safe substance because of its low toxicity. However, its molecular structure is susceptible to changes in pH, oxidation, photodegradation, low aqueous solubility, and biotransformation compromising its bioavailability; these drawbacks are successfully addressed through nanotechnology.

OBJECTIVE

The present review systematizes findings on the enhancement of curcumin's beneficial effects when it is loaded and co-loaded into different types of nanosystems covering liposomes, polymeric and solid-lipid nanoparticles, nanostructured lipid carrier, lipid-polymeric hybrids, self- -assembled and protein-based core-shell systems in relation to its antimicrobial, antioxidant, anti-inflammatory and central nervous system protective bioactivities.

CONCLUSION

Curcumin is a versatile molecule capable of exerting antimicrobial, antioxidant, anti- inflammatory, and central nervous system protective effects in an enhanced manner using the possibilities offered by the nanotechnology-based approach. Its enhanced bioactivities are associated with increments in solubility, stability, bioavailability, as well as in improved intracellular uptake and cell internalization. These advantages, in addition to curcumin's low toxicity, indicate the potential of curcumin to be loaded and co-loaded into nanosystems capable of providing a controlled release and targeted administration.

Silk Nanoparticles: A Natural Polymeric Platform for Nitric Oxide Delivery in Biomedical Applications

In this study, the preparation and characterization of nitric oxide (NO) releasing silk fibroin nanoparticles (SF NPs) are described for the first time. S-Nitroso-N-acetylpenicillamine (SNAP)-loaded SF NPs (SNAP-SF NPs) were prepared via an antisolvent/self-assembling method by adding a SNAP/ethanol solution to an aqueous SF solution and freeze-thawing. The prepared SNAP-SF NPs had a diameter ranging from 300 to 400 nm and an overall negative charge of -28.76 ± 0.73 mV. Among the different SNAP/SF ratios tested, the highest encapsulation efficiency (18.3 ± 1.3%) and loading capacity (9.1 ± 0.6%) values were attributed to the 1:1 ratio. The deconvolution of the amide I band in the FTIR spectra of SF NPs and SNAP-SF NPs showed an increase in the β-sheet content for SNAP-SF NPs, confirming the hydrophobic interactions between SNAP and silk macromolecules. SNAP-SF NPs released up to 1.31 ± 0.02 × 10^-10 mol min^-1 mg^-1 NO over a 24 h period. Moreover, SNAP-SF NPs showed concentration-dependent antibacterial effects against methicillin-resistant Staphylococcus aureus and Escherichia coli. Furthermore, they did not elicit any marked cytotoxicity against 3T3 mouse fibroblast cells at concentrations equal to or below 2 mg/mL. Overall, these results demonstrated that SNAP-SF NPs have great potential to be used as a NO delivery platform for biomedical applications such as tissue engineering and wound healing, where synergistic properties of SF and NO are desired.

Recent Advances in Extracellular Vesicles as Drug Delivery Systems and Their Potential in Precision Medicine

Extracellular vesicles (EVs) are membrane-bilayered nanoparticles released by most cell types. Recently, an enormous number of studies have been published on the potential of EVs as carriers of therapeutic agents. In contrast to systems such as liposomes, EVs exhibit less immunogenicity and higher engineering potential. Here, we review the most relevant publications addressing the potential and use of EVs as a drug delivery system (DDS). The information is divided based on the key steps for designing an EV-mediated delivery strategy. We discuss possible sources and isolation methods of EVs. We address the administration routes that have been tested in vivo and the tissue distribution observed. We describe the current knowledge on EV clearance, a significant challenge towards enhancing bioavailability. Also, EV-engineering approaches are described as alternatives to improve tissue and cell-specificity. Finally, a summary of the ongoing clinical trials is performed. Although the application of EVs in the clinical practice is still at an early stage, a high number of studies in animals support their potential as DDS. Thus, better treatment options could be designed to precisely increase target specificity and therapeutic efficacy while reducing off-target effects and toxicity according to the individual requirements of each patient.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: Opportunities and Challenges for Clinical Translation

Extracellular vesicles (EVs), including exosomes and microvesicles, derived from mesenchymal stem/stromal cells (MSCs) exert similar effects as their parental cells, and are of interest for various therapeutic applications. EVs can act through uptake by the target cells followed by release of their cargo inside the cytoplasm, or through interaction of membrane-bound ligands with receptors expressed on target cells to stimulate downstream intracellular pathways. EV-based therapeutics may be directly used as substitutes of intact cells or after modification for targeted drug delivery. However, for the development of EV-based therapeutics, several production, isolation, and characterization requirements have to be met and the quality of the final product has to be tested before its clinical implementation. In this review, we discuss the challenges associated with the development of EV-based therapeutics and the regulatory specifications for their successful clinical translation.

GMP-compliant sponge-like dressing containing MSC lyo-secretome: Proteomic network of healing in a murine wound model

Chronic wounds account for 3% of total healthcare expenditure of developed countries; thus, innovative therapies, including Mesenchymal Stem Cells (MSCs) end their exosomes are increasingly considered, even if the activity depends on the whole secretome, made of both soluble proteins and extracellular vesicles. In this work, we prove for the first time the in vivo activity of the whole secretome formulated in a sponge-like alginate wound dressing to obtain the controlled release of bioactive substances. The product has been prepared in a public GMP-compliant facility by a scalable process; based on the murine model, treated wounds healed faster than controls without complications or infections. The treatment induced a higher acute inflammatory process in a short time and sustained the proliferative phase by accelerating fibroblast migration, granulation tissue formation, neovascularization and collagen deposition. The efficacy was substantially supported by the agreement between histological and proteomic findings. In addition to functional modules related to proteolysis, complement and coagulation cascades, protein folding and ECM remodeling, in treated skin, emerged the role of specific wound healing related proteins, including Tenascin (Tnc), Decorin (Dcn) and Epidermal growth factor receptor (EGFR). Of note, Decorin and Tenascin were also components of secretome, and network analysis suggests a potential role in regulating EGFR. Although further experiments will be necessary to characterize better the molecular keys induced by treatment, overall, our results confirm the whole secretome efficacy as novel "cell-free therapy". Also, sponge-like topical dressing containing the whole secretome, GMP- compliant and "ready-off-the-shelf", may represent a relevant point to facilitate its translation into the clinic.

Polyphenols-Loaded Sericin Self-Assembling Nanoparticles: A Slow-Release for Regeneration by Tissue-Resident Mesenchymal Stem/Stromal Cells

Mesenchymal stem/stromal cells (MSCs) are a therapeutic target to promote tissue regeneration, mainly when oxidative stress-mediated damage is involved in disease pathogenesis. Here, slow-release silk sericin nanoparticles (SNPs) loaded with natural antioxidant polyphenols were developed to sustain regeneration by tissue-resident MSCs. SNPs were prepared by exploiting a self-assembly method with poloxamer and were loaded with proanthocyanidins (P), quercetin (Q) or epigallocatechin gallate (E). SNPs, with a diameter less than 150 nm, were able to encapsulate both hydrophilic (P and E) and hydrophobic (Q) drugs. A slow and controlled release was obtained from SNPs for all the actives in PBS, while in EtOH, Q and E showed a burst release but P did not. Kinetic models revealed lower diffusion of P than other biomolecules, probably due to the higher steric hindrance of P. The in vitro anti-oxidant, anti-elastase and anti-tyrosinase properties of SNPs were assessed: loading the P and E into SNPs preserved the in vitro biological activities whereas for Q, the anti-elastase activity was strongly improved. Moreover, all formulations promoted MSC metabolic activity over 72 h. Finally, SNPs exhibited a strong ability to protect MSCs from oxidative stress, which supports their potential use for regenerative purposes mediated by tissue-resident MSCs.

Steering the Clinical Translation of Delivery Systems for Drugs and Health Products

Besides the feasibility for industrial scale-up, accelerating the translation from bench to bedside of new technological strategies for controlled delivery and targeting of drugs and other actives relevant for health management, such as medical devices and nutraceuticals, would benefit from an even earlier evaluation in pre-clinical models and clinical settings. At the same time, translational medicine also performs in the opposite direction, incorporating clinical needs and observations into scientific hypotheses and innovative technological proposals. With these aims, the sessions proposed for the 2019 CRS Italy Chapter Workshop will introduce the experience of Italian and worldwide researchers on how to foster the actual work in controlled release and drug delivery towards a reliable pre-clinical and clinical assessment.

Chromatographic profiling of silk sericin for biomedical and cosmetic use by complementary hydrophylic, reversed phase and size exclusion chromatographic methods

Silk sericin (SS) is, together with silk fibroin (SF), one of the two proteins forming the silkworm cocoon. SS is ideal ingredient for cosmetic applications in the formulation of specific products for skin care and hair due to its peculiar physical-chemical composition. SS also showed a great potential in different pharmacological and biotechnological applications, as anticancer drug, anticoagulant, cell culture additive, wound healing agent and drug delivery carrier. Reasons for SS use in biomedical applications derive from its physical-chemical composition. As a consequence, a detailed characterization of SS in terms of average molecular weight, molecular weight distribution and hydro/lipophilic character is crucial to properly address and assess its quality, cosmetic or pharmacological use. In this study, the application of different and complementary chromatographic modes allows a detailed investigation of SS protein isolated from wastewater using two diverse extraction methods. Hydrophilic interaction liquid chromatography (HILIC using an AdvanceBio Glycan Map column) and reverse phase (RP using Symmetry300 C18 column) were applied to intact protein characterization to derive data on protein hydrophilicity and on hydrophobic components of the two SS preparations (SS#1 and SS#2). A higher hydrophilic character of SS#1 was observed by HILIC trace, coherently with the preparation method used, while no significant differences in hydrophobicity were detectable in the RPLC separations. Size distribution was also defined by using a SEC-UV-MS method (using TSKgel SuperSW2000 column) properly optimized to maximize both the size selectivity and the method sensitivity. Taken together, the chromatographic data allowed to better characterize the SS samples obtained by different extraction methods, and the structural properties were correlated to their biological activities.

Therapeutic Advances of Stem Cell-Derived Extracellular Vesicles in Regenerative Medicine

Extracellular vesicles (EVs), which are the main paracrine components of stem cells, mimic the regenerative capacity of these cells. Stem cell-derived EVs (SC-EVs) have been used for the treatment of various forms of tissue injury in preclinical trials through maintenance of their stemness, induction of regenerative phenotypes, apoptosis inhibition, and immune regulation. The efficiency of SC-EVs may be enhanced by selecting the appropriate EV-producing cells and cell phenotypes, optimizing cell culture conditions for the production of optimal EVs, and further engineering the EVs produced to transport therapeutic and targeting molecules.

Genetic labeling of extracellular vesicles for studying biogenesis and uptake in living mammalian cells

Molecular imaging methods are powerful tools for gaining insight into the cellular organization of living cells. To understand the biogenesis and uptake of extracellular vesicles (EVs) as well as to engineer cell-derived vesicles for targeted drug delivery and therapy, genetic labeling with fluorescent proteins has increasingly been used to determine the structures, locations, and dynamics of EVs in vitro and in vivo. Here, we report a genetic method for the stable labeling of EVs to study their biogenesis and uptake in living human cells. Fusing a green fluorescent protein (GFP) with either the endogenous CD63 (CD63-GFP) or a vesicular stomatitis virus envelope glycoprotein, VSVG (VSVG-GFP), we successfully obtained distinct fluorescence signals in the cytoplasm, revealing the biogenesis of EVs in post-transfected cells. We describe experimental procedures in detail for EV isolation, imaging, and cellular uptake using both confocal microscopy and flow cytometry. We also provide a perspective on how genetic labeling methods can be used to study EV biology, characterization of engineered EVs, and development of EV-based nano-medicine.

Emergence in protein derived nanomedicine as anticancer therapeutics: More than a tour de force

Cancer has thwarted as a major health problem affecting the global population. With an alarming increase in the patient population suffering from diverse varieties of cancers, the global demographic data predicts sharp escalation in the number of cancer patients. This can be expected to reach 420 million cases by 2025. Among the diverse types of cancers, the most frequently diagnosed cancers are the breast, colorectal, prostate and lung cancer. From years, conventional treatment approaches like surgery, chemotherapy and radiation therapy have been practiced. In the past few years, increasing research on molecular level diagnosis and treatment of cancers have significantly changed the realm of cancer treatment. Lately, uses of advanced chemotherapy and immunotherapy like treatments have gained significant progress in the cancer therapy, but these approaches have several limitations on their safety and toxicity. This has generated lot of momentum for the evolution of new drug delivery approaches for the effective delivery of anticancer therapeutics, which may improve the pharmacokinetic and pharmacodynamic effect of the drugs along with significant reduction in the side effects. In this regard, the protein-based nano-medicines have gained wider attention in the management of cancer. Proteins are organic macromolecules essential, for life and have quite well explored in developing the nano-carriers. Furthermore, it provides passive or active tumour cell targeted delivery, by using protein based nanovesicles or virus like structures, antibody drug conjugates, viral particles, etc. Moreover, by utilizing various formulation strategies, both the animal and plant derived proteins can be converted to produce self-assembled virus like nano-metric structures with high efficiency in targeting the metastatic cancer cells. Therefore, the present review extensively discusses the applications of protein-based nano-medicine with special emphasis on intracellular delivery/drug targeting ability for anticancer drugs.

Extended release formulations using silk proteins for controlled delivery of therapeutics

INTRODUCTION

Silk is a promising biomaterial for controlled delivery of therapeutics and has a unique protein chemistry that can be tuned to form different carrier formats. The protein has been studied for sustained release depot systems for the targeted or localized delivery of drugs.

AREAS COVERED

An overview of natural silk proteins for controlled delivery of therapeutics is provided, with a focus on the features of silk proteins that allow them to be useful tools for controlled delivery. Recent applications of natural silk proteins as controlled delivery systems are also summarized.

EXPERT OPINION

The versatility of silk proteins makes them desirable biomaterials for a broad range of applications for controlled delivery of both small and large molecules. Further, the degradation profile leading to peptides and amino acids provides compatibility with pH-sensitive therapeutics. While silk sericin and spider silks are under study, silk fibroin extracted from silkworms (e.g. Bombyx mori) dominates pharmaceutical studies with silk. Silk fibroin can be formed into drug delivery tools for systemic or local injections, topical and transdermal applications, and implantation; depending on the target disease and therapeutic molecule. In vitro to in vivo correlations and scale-up needs are the next steps towards clinical applications.

Mesenchymal Stem Cell (MSC)-Derived Extracellular Vesicles: Potential Therapeutics as MSC Trophic Mediators in Regenerative Medicine

Mesenchymal stem cells (MSCs) are pluripotent progenitor cells with the capabilities of self-renewing, differentiating into multiple lineages, and achieving trophic effects during tissue repair. MSCs can secrete extracellular vesicles (EVs) including exosomes and microvesicles, which mediate their trophic effects on other cells. Carrying a variety of intracellular molecules of MSCs including lipids, proteins, RNA (mRNA and noncoding RNA), and DNA, EVs deliver them into other cells to regulate tissue regeneration process. The therapeutic effects of MSC-derived EVs have been observed in a number of animal disease models. In this review, we focus on the current state and future directions of MSC-derived EVs in regenerative medicine. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.

Paclitaxel-Loaded Silk Fibroin Nanoparticles: Method Validation by UHPLC-MS/MS to Assess an Exogenous Approach to Load Cytotoxic Drugs

The aim of this work was to load an anticancer drug, paclitaxel (PTX), on Silk Fibroin Nanoparticles (SFNs) by using an exogenous approach. SFNs were produced, freeze-dried and then loaded with PTX. An exogenous method allowed us to reduce both drug loss and environmental impact. In order to quantify PTX loaded in SFNs, a simple and reliable method using reversed phase liquid chromatography coupled to tandem mass spectrometry (rp-UHPLC-MS/MS) was developed. This methodology was validated by the determination of spiked QC samples in three consecutive days. Good accuracy and precision of the method were obtained, while the intra-day and inter-day precisions were less than 10.3%. For PTX, the limit of quantitation (LOQ) was 5.0 ng/mL. Recovery from the matrix (SFNs-PTX pellets) was calculated (81.2% at LOQ value) as PTX was entrapped in a new matrix like the polymer silk fibroin-based. This method was successfully applied to determine the encapsulation efficiency (1.00 ± 0.19%) and the nanoparticle loading (0.12 ± 0.02% w/w). The in vitro anticancer activity of SFNs-PTX was tested against CFPAC-1 cancer cells; results demonstrated a very high cytotoxic activity of SFNs-PTX, with a dose dependent inhibition of CFPAC-1 proliferation, confirmed by the IC50 value of 3450 ± 750 ng/mL.

Taxol-Loaded MSC-Derived Exosomes Provide a Therapeutic Vehicle to Target Metastatic Breast Cancer and Other Carcinoma Cells

MSC-derived exosomes display, among others, an efficient biocompatibility and a reduced intrinsic immunogenicity, representing a valuable vehicle for drug delivery in a tumor-therapeutic approach. Following treatment of several human mesenchymal stroma/stem-like cell (MSC) populations with sub-lethal concentrations of taxol for 24 h, exosomes were isolated and applied to different human cancer populations including A549 lung cancer, SK-OV-3 ovarian cancer, and MDA-hyb1 breast cancer cells. While MSC control exosomes revealed little if any growth inhibition on the tumor cells, exposure to taxol-loaded MSC-derived exosomes was associated with 80–90% cytotoxicity. A similar application of taxol-loaded exosomes from HuVEC displayed much fewer effects. Quantification by LC-MS/MS analysis demonstrated a 7.6-fold reduced taxol concentration in MSC exosomes when compared to equivalent cytotoxic in vitro effects achieved with taxol substances, indicating a specific and more efficient tumor-targeting property. Consequently, MSC-derived taxol exosomes were tested in vivo. Highly metastatic MDA-hyb1 breast tumors were induced in NODscid mice, and systemic intravenous application of MSC-derived taxol exosomes revealed a more than 60% reduction of subcutaneous primary tumors. Moreover, the amount of distant organ metastases observed at least in lung, liver, spleen, and kidney was reduced by 50% with MSC taxol exosomes, similar to the effects observed with taxol, although the concentration of taxol in exosomes was about 1000-fold reduced. Together, these findings in different cancer cell populations and in vivo provide promising future perspectives for drug-loaded MSC-derived exosomes in efficiently targeting primary tumors and metastases by reducing side effects.

Freeze-dried and GMP-compliant pharmaceuticals containing exosomes for acellular mesenchymal stromal cell immunomodulant therapy

Aim: To validate the use of ultrafiltration (UF) as an alternative applicable industrial method to replace ultracentrifugation (UC) in the purification of mesenchymal stromal cell (MSC)-secretome. Materials & methods: Pharmaceutical formulations containing secretome and/or extracellular vesicles were extracted from adipose-MSCs and bone marrow-MSCs by combining UF or UC with lyophilization. Results & conclusion: UF led to higher protein, lipid, cytokine and exosomes yields compared with UC. The isolation procedure and cell source influenced immunomodulatory activity, which was in vitro evaluated by inhibition of phytohemagglutinin-activated peripheral blood mononuclear cell proliferation, and by modulation of IL-10, IFN-γ and IL-6. A secretome dosage was identified to obtain the same immunomodulatory activity of MSCs, paving the way for cell-free therapy.

Biological Activity and Pharmacological Application of Pectic Polysaccharides: A Review

Pectin is a polymer with a core of alternating α-1,4-linked d-galacturonic acid and α-1,2-l-rhamnose units, as well as a variety of neutral sugars such as arabinose, galactose, and lesser amounts of other sugars. Currently, native pectins have been compared to modified ones due to the development of natural medicines and health products. In this review, the results of a study of the bioactivity of pectic polysaccharides, including its various pharmacological applications, such as its immunoregulatory, anti-inflammatory, hypoglycemic, antibacterial, antioxidant and antitumor activities, have been summarized. The potential of pectins to contribute to the enhancement of drug delivery systems has been observed.

Pilot Production of Mesenchymal Stem/Stromal Freeze-Dried Secretome for Cell-Free Regenerative Nanomedicine: A Validated GMP-Compliant Process

In this paper, a pilot production process for mesenchymal stem/stromal freeze-dried secretome was performed in a validated good manufacturing practice (GMP)-compliant cell factory. Secretome was purified from culture supernatants by ultrafiltration, added to cryoprotectant, lyophilized and characterized. We obtained a freeze-dried, "ready-off-the-shelf" and free soluble powder containing extracellular vesicles and proteins. In the freeze-dried product, a not-aggregated population of extracellular vesicles was detected by nanoparticle tracking analysis; Fourier transform infrared spectra showed the simultaneous presence of protein and lipids, while differential scanning calorimetry demonstrated that lyophilization process successfully occurred. A proteomic characterization allowed the identification of proteins involved in immune response, response to stress, cytoskeleton and metabolism. Moreover, the product was not cytotoxic up to concentrations of 25 mg/mL (on human fibroblasts, chondrocytes and nucleus pulposus cells by MTT assay) and was blood compatible up to 150 mg/mL. Finally, at concentrations between 5 and 50 mg/mL, freeze-dried secretome showed to in vitro counteract the oxidative stress damage induced by H₂O₂ on nucleus pulposus cells by MTT assay.

Comparison of exosome-mimicking liposomes with conventional liposomes for intracellular delivery of siRNA

Exosomes have been extensively explored as delivery vehicles due to low immunogenicity, efficient cargo delivery, and possibly intrinsic homing capacity. However, therapeutic application of exosomes is hampered by structural complexity and lack of efficient techniques for isolation and drug loading. Liposomes represent one of the most successful therapeutic nanocarriers, but are frequently criticized by short blood circulation and inefficient intracellular drug delivery. In this circumstance, a promising strategy is to facilitate a positive feedback between two fields. Herein, exosome-mimicking liposomes were formulated with DOPC/SM/Chol/DOPS/DOPE (21/17.5/30/14/17.5, mol/mol), and harnessed for delivery of VEGF siRNA to A549 and HUVEC cells. Compared with Lipo 2000 and DOTAP liposomes, exosome-mimicking liposomes exhibited less than four-fold cytotoxicity but higher storage stability and anti-serum aggregation effect. Exosome-mimicking liposomes appeared to enter A549 cells through membrane fusion, caveolae-mediated endocytosis, and macropinocytosis, while enter HUVEC through caveolae-mediated endocytosis, which revealed that the uptake pathway was dependent on cell types. Notably, exosome-mimicking liposomes exhibited significantly higher cellular uptake and silencing efficiency than PC-Chol liposomes (>three-fold), suggesting the unique lipid composition did enhance the intracellular delivery efficiency of exosome-mimicking liposomes to a significantly greater extent. However, it still remained far from satisfactory delivery as compared to cationic Lipo 2000 and DOTAP liposomes, which warranted further improvement in future research. This study may encourage further pursuit of more exosome-mimicking delivery vehicles with higher efficiency and biocompatibility.

Potential Non-neoplastic Applications for Polyphenols in Stem Cell Utilization

While polyphenols may have important effects on pluripotential stem cells that make them noteworthy as potential antineoplastic agents, their action on stem cells may portend other health benefits, such as treatments for cardiovascular and neurocognitive disorders. Resveratrol, the beststudied polyphenol, has been found to enable stem cells to differentiate into cardiomyocytes, neurons, osteocytes, and pancreatic beta cells, as well as facilitating augmentation of stem cell populations and protecting them from toxic injury. Curcumin protects mesenchymal stem cells from toxicity, and prevents them from facilitating chondrocytic hypertrophy. Quercetin enabled osteocytic and pancreatic beta cell differentiation, and protected neuronal stem cells from injury. Epigallocatechin gallate prevented damage to osteocyte precursors and averted differentiation into undesirable adipocytes. Genistein facilitated osteogenesis while preventing adipogenesis. Several other polyphenols, daidzein, caffeic and chlorogenic acid, kaempferol, and piceatannol, protect stems cells from reactive oxygen species and foster stem cells differentiation away from adipocytic and toward osteocytic lineages. Further research should better elucidate the pharmacokinetic profiles of each polyphenol, explore novel delivery systems, and expand investigation beyond rodent models to additional species.

The extracellular vesicles-derived from mesenchymal stromal cells: A new therapeutic option in regenerative medicine

Mesenchymal stem cells (MSCs) are adult multipotent cells that due to their ability to homing to damaged tissues and differentiate into specialized cells, are remarkable cells in the field of regenerative medicine. It's suggested that the predominant mechanism of MSCs in tissue repair might be related to their paracrine activity. The utilization of MSCs for tissue repair is initially based on the differentiation ability of these cells; however now it has been revealed that only a small fraction of the transplanted MSCs actually fuse and survive in host tissues. Indeed, MSCs supply the microenvironment with the secretion of soluble trophic factors, survival signals and the release of extracellular vesicles (EVs) such as exosome. Also, the paracrine activity of EVs could mediate the cellular communication to induce cell-differentiation/self-renewal. Recent findings suggest that EVs released by MSCs may also be critical in the physiological function of these cells. This review provides an overview of MSC-derived extracellular vesicles as a hopeful opportunity to advance novel cell-free therapy strategies that might prevail over the obstacles and risks associated with the use of native or engineered stem cells. EVs are very stable; they can pass the biological barriers without rejection and can shuttle bioactive molecules from one cell to another, causing the exchange of genetic information and reprogramming of the recipient cells. Moreover, extracellular vesicles may provide therapeutic cargo for a wide range of diseases and cancer therapy.

Production of Curcumin-Loaded Silk Fibroin Nanoparticles for Cancer Therapy

Curcumin, extracted from the rhizome of Curcuma longa, has been widely used in medicine for centuries due to its anti-inflammatory, anti-cancer, anti-oxidant and anti-microbial effects. However, its bioavailability during treatments is poor because of its low solubility in water, slow dissolution rate and rapid intestinal metabolism. For these reasons, improving the therapeutic efficiency of curcumin using nanocarriers (e.g., biopolymer nanoparticles) has been a research focus, to foster delivery of the curcumin inside cells due to their small size and large surface area. Silk fibroin from the Bombyx mori silkworm is a biopolymer characterized by its biocompatibility, biodegradability, amphiphilic chemistry, and excellent mechanical properties in various material formats. These features make silk fibroin nanoparticles useful vehicles for delivering therapeutic drugs, such as curcumin. Curcumin-loaded silk fibroin nanoparticles were synthesized using two procedures (physical adsorption and coprecipitation) more scalable than methods previously described using ionic liquids. The results showed that nanoparticle formulations were 155 to 170 nm in diameter with a zeta potential of approximately -45 mV. The curcumin-loaded silk fibroin nanoparticles obtained by both processing methods were cytotoxic to carcinogenic cells, while not decreasing viability of healthy cells. In the case of tumor cells, curcumin-loaded silk fibroin nanoparticles presented higher efficacy in cytotoxicity against neuroblastoma cells than hepatocarcinoma cells. In conclusion, curcumin-loaded silk fibroin nanoparticles constitute a biodegradable and biocompatible delivery system with the potential to treat tumors by local, long-term sustained drug delivery.