Reversible thermal regulation for bifunctional dynamic control of gene expression in Escherichia coli

Genetically programmed circuits allowing bifunctional dynamic regulation of enzyme expression have far-reaching significances for various bio-manufactural purposes. However, building a bio-switch with a post log-phase response and reversibility during scale-up bioprocesses is still a challenge in metabolic engineering due to the lack of robustness. Here, we report a robust thermosensitive bio-switch that enables stringent bidirectional control of gene expression over time and levels in living cells. Based on the bio-switch, we obtain tree ring-like colonies with spatially distributed patterns and transformer cells shifting among spherical-, rod- and fiber-shapes of the engineered Escherichia coli. Moreover, fed-batch fermentations of recombinant E. coli are conducted to obtain ordered assembly of tailor-made biopolymers polyhydroxyalkanoates including diblock- and random-copolymer, composed of 3-hydroxybutyrate and 4-hydroxybutyrate with controllable monomer molar fraction. This study demonstrates the possibility of well-organized, chemosynthesis-like block polymerization on a molecular scale by reprogrammed microbes, exemplifying the versatility of thermo-response control for various practical uses.

Key Factor Study for Generic Long-Acting PLGA Microspheres Based on a Reverse Engineering of Vivitrol®

The FDA (U.S. Food and Drug Administration) has approved only a negligible number of poly(lactide-co-glycolide) (PLGA)-based microsphere formulations, indicating the difficulty in developing a PLGA microsphere. A thorough understanding of microsphere formulations is essential to meet the challenge of developing innovative or generic microspheres. In this study, the key factors, especially the key process factors of the marketed PLGA microspheres, were revealed for the first time via a reverse engineering study on Vivitrol^® and verified by the development of a generic naltrexone-loaded microsphere (GNM). Qualitative and quantitative similarity with Vivitrol^®, in terms of inactive ingredients, was accomplished by the determination of PLGA. Physicochemical characterization of Vivitrol^® helped to identify the critical process parameters in each manufacturing step. After being prepared according to the process parameters revealed by reverse engineering, the GNM demonstrated similarity to Vivitrol^® in terms of quality attributes and in vitro release (f₂ = 65.3). The research on the development of bioequivalent microspheres based on the similar technology of Vivitrol^® will benefit the development of other generic or innovative microspheres.

The application of multifunctional nanomaterials in Alzheimer's disease: A potential theranostics strategy

By virtue of their small size, nanomaterials can cross the blood-brain barrier and, when modified to target specific cells or regions, can achieve high bioavailability at the intended site of action. Modified nanomaterials are therefore promising agents for the diagnosis and treatment of neurodegenerative diseases such as Alzheimer's disease (AD). Here we review the roles and mechanisms of action of nanomaterials in AD. First, we discuss the general characteristics of nanomaterials and their application to nanomedicine. Then, we summarize recent studies on the diagnosis and treatment of AD using modified nanomaterials. These studies indicate that using nanomaterials is a potential strategy for AD treatment by slowing the progression of AD through enhanced therapeutic effects.

Novel Use of PLGA Microspheres to Create an Animal Model of Glaucoma with Progressive Neuroretinal Degeneration

Progressive degeneration of neuroretinal tissue with maintained elevated intraocular pressure (IOP) to simulate chronic glaucoma was produced by intracameral injections of poly (lactic-co-glycolic) acid (PLGA) microspheres (Ms) in rat eyes. The right eye of 39 rats received different sizes of PLGA-Ms (2 µL suspension; 10% w/v): 14 with 38–20 µm Ms (Ms38/20 model) and 25 with 20–10 µm particles (Ms20/10 model). This novel glaucoma animal model was compared to the episcleral vein sclerosis (EPI) model (25 eyes). Injections were performed at baseline, two, four and six weeks. Clinical signs, IOP, retina and optic nerve thicknesses (using in vivo optical coherence tomography; OCT), and histological studies were performed. An IOP increment was observed in all three groups, however, the values obtained from the PLGA-Ms injection resulted lower with a better preservation of the ocular surface. In fact, the injection of Ms20/10 created a gentler, more progressive, and more sustained increase in IOP. This IOP alteration was correlated with a significant decrease in most OCT parameters and in histological ganglion-cell count for the three conditions throughout the eight-week follow-up. In all cases, progressive degeneration of the retina, retinal ganglion cells and optic nerve, simulating chronic glaucoma, was detected by OCT and corroborated by histological study. Results showed an alternative glaucoma model to the well-known episcleral vein model, which was simpler to perform, more reproducible and easier to monitor in vivo.

Novel insights on the encapsulation mechanism of PLGA terminal groups on ropivacaine

Currently, the influences of free terminal groups (hydroxyl, carboxyl and ester) of PLGA on encapsulating active pharmaceutical ingredient are relatively ambiguous even though PLGA types were defined as critical quality attributes in vast majority of design of experiment process. In this study, emulsion method combined with premix membrane emulsification technique has been used to encapsulate ropivacaine (RVC), a small molecule local anesthetic in clinical. Based on the narrow particle size distribution, the influences and mechanisms of the terminal groups on properties of ropivacaine loaded microspheres have been investigated in detail. It was found that microspheres prepared by PLGA with hydroxyl or ester groups exhibited lower encapsulation efficiency but faster in vitro release rate than that of carboxyl groups. In the meanwhile, on microcosmic level analysis by quartz crystal microbalance with dissipation, atomic force microscope and confocal laser scanning microscopy, we attributed this distinction to the specific interaction between ropivacaine and different terminal groups. Subsequently, the reaction activation centers were verified by density functional simulation calculation and frontier molecular orbital theory at molecular level. Additionally, pharmacokinetics and pharmacodynamic research of infiltration anesthesia model were performed to compare sustained release ability, duration and intensity of the anesthetic effect in vivo. Finally, potential safety and toxicity were evaluated by the biochemical analysis. This study not only provides a novel mechanism of drug encapsulation process but also potential flexible selections in terms of various anesthesia indications in clinical.

Development of a Biodegradable Microcarrier for the Cultivation of Human Adipose Stem Cells (hASCs) with a Defined Xeno- and Serum-Free Medium

Stirred single-use bioreactors in combination with microcarriers (MCs) have established themselves as a technology that has the potential to meet the demands of current and future cell therapeutic markets. However, most of the published processes have been performed using fetal bovine serum (FBS) containing cell culture medium and non-biocompatible MCs. This approach has two significant drawbacks: firstly, the inevitable potential risks associated with the use of FBS for clinical applications; secondly, non-biocompatible MCs have to be removed from the cell suspension before implantation, requiring a step that causes loss of viable cells and adds further costs and complications. This study aimed to develop a new platform based on a chemically defined xeno- and serum-free cell culture medium and biodegradable MC that can support the growth of human adipose stem cells (hASCs) while still preserving their undifferentiated status. A specific combination of components and manufacturing parameters resulted in a MC prototype, called “BR44”, which delivered the desired functionality. MC BR44 allows the hASCs to stick to its surface and grow in a chemically defined xeno- and serum-free medium (UrSuppe). Although the cells’ expansion rate was not as high as with a commercial non-biodegradable standard MC, those cultured on BR44 maintained a better undifferentiated status in both static and dynamic conditions than those cultured on traditional 2D surfaces.

Engineering microenvironment of biodegradable polyester systems for drug stability and release control

Polymeric systems made of poly(lactic acid) or poly(lactic-co-glycolic acid) are widely used for long-term delivery of small and large molecules. The advantages of poly(lactic acid)/poly(lactic-co-glycolic acid) systems include biodegradability, safety and a long history of use in US FDA-approved products. However, as drugs delivered by the polymeric systems and their applications become more diverse, the significance of microenvironment change of degrading systems on long-term drug stability and release kinetics has gained renewed attention. In this review, we discuss various issues experienced with acidifying microenvironment of biodegradable polymer systems and approaches to overcome the detrimental effects of polymer degradation on drug stability and release control.

Stem cells and growth factors-based delivery approaches for chronic wound repair and regeneration: A promise to heal from within

The sophisticated chain of cellular and molecular episodes during wound healing includes cell migration, cell proliferation, deposition of extracellular matrix, and remodelling and are onerous to replicate. Encapsulation of growth factors (GFs) and Stem cell-based (SCs) has been proclaimed to accelerate healing by transforming every phase associated with wound healing to enhance skin regeneration. Therapeutic application of mesenchymal stem cells (MSCs), embryonic stem cells (ESCs) and induced pluripotent stem cells (PSCs) provides aid in wound fixing, tissue integrity restoration and function of impaired tissue. Several scientific studies have established the essential role GFs in wound healing and their reduced degree in the chronic wound. The overall limitation includes half-life, unfriendly microhabitat abundant with protease, and inadequate delivery approaches results in decreased delivery of effective amounts in a suitable time-based fashion. Advancements in the area of reformative medicine as well as tissue engineering have offered techniques competent of dispensing SCs and GFs in site-oriented manner. The progress in nanotechnology-based approaches attracts researcher to study and evaluate the potential of this SCs and GFs based therapy in chronic wounds. These techniques embrace the polymeric regime viz., nano-formulations, hydrogels, liposomes, scaffolds, nanofibers, metallic nanoparticles, lipid-based nanoparticles and dendrimers that have established better retort through targeting tissues when GFs and SCs are transported via these humans made devices. Assumed the current problems, improvements in delivery approaches and difficulties offered by chronic wounds, we hope to show that encapsulation of SCs and GFs loaded nanoformulations therapies is the rational next step in improving wound care.

CRISPR Technology for Ocular Angiogenesis

Among genome engineering tools, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based approaches have been widely adopted for translational studies due to their robustness, precision, and ease of use. When delivered to diseased tissues with a viral vector such as adeno-associated virus, direct genome editing can be efficiently achieved in vivo to treat different ophthalmic conditions. While CRISPR has been actively explored as a strategy for treating inherited retinal diseases, with the first human trial recently initiated, its applications for complex, multifactorial conditions such as ocular angiogenesis has been relatively limited. Currently, neovascular retinal diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and neovascular age-related macular degeneration, which together constitute the majority of blindness in developed countries, are managed with frequent and costly injections of anti-vascular endothelial growth factor (anti-VEGF) agents that are short-lived and burdensome for patients. By contrast, CRISPR technology has the potential to suppress angiogenesis permanently, with the added benefit of targeting intracellular signals or regulatory elements, cell-specific delivery, and multiplexing to disrupt different pro-angiogenic factors simultaneously. However, the prospect of permanently suppressing physiologic pathways, the unpredictability of gene editing efficacy, and concerns for off-target effects have limited enthusiasm for these approaches. Here, we review the evolution of gene therapy and advances in adapting CRISPR platforms to suppress retinal angiogenesis. We discuss different Cas9 orthologs, delivery strategies, and different genomic targets including VEGF, VEGF receptor, and HIF-1α, as well as the advantages and disadvantages of genome editing vs. conventional gene therapies for multifactorial disease processes as compared to inherited monogenic retinal disorders. Lastly, we describe barriers that must be overcome to enable effective adoption of CRISPR-based strategies for the management of ocular angiogenesis.

CD44-Targeting Oxygen Self-Sufficient Nanoparticles for Enhanced Photodynamic Therapy Against Malignant Melanoma

Objective

Nanotechnology-based photodynamic therapy (PDT) is a relatively new anti-tumor strategy. However, its efficacy is limited by the hypoxic state in the tumor microenvironment. In the present study, a poly(lactic-co-glycolic acid) (PLGA) nanoparticle that encapsulated both IR820 and catalase (CAT) was developed to enhance anti-tumor therapy.

Materials and Methods

HA-PLGA-CAT-IR820 nanoparticles (HCINPs) were fabricated via a double emulsion solvent evaporation method. Dynamic light scattering (DLS), transmission electron microscopy (TEM), laser scanning confocal microscopy, and an ultraviolet spectrophotometer were used to identify and characterize the nanoparticles. The stability of the nanoparticle was investigated by DLS via monitoring the sizes and polydispersity indexes (PDIs) in water, PBS, DMEM, and DMEM+10%FBS. Oxygen generation measurement was carried out via visualizing the oxygen bubbles with ultrasound imaging system and an optical microscope. Inverted fluorescence microscopy and flow cytometry were used to measure the uptake and targeting effect of the fluorescent-labeled nanoparticles. The live-dead method and tumor-bearing mouse models were applied to study the HCINP-induced enhanced PDT effect.

Results

The results showed that the HCINPs could selectively target melanoma cells with high expression of CD44, and generated oxygen by catalyzing H₂O₂, which increased the amount of singlet oxygen, ultimately inhibiting tumor growth significantly.

Conclusion

The present study presents a novel nanoplatform for melanoma treatment.

In vitro and in vivo evaluation of a ciprofloxacin delivery system based on poly(DLLA-co-GA-co-CL) for treatment of chronic osteomyelitis

Chronic osteomyelitis causes serious injury to patients. Antibiotic delivery systems based on poly(lactide-co-glycolide) (PLGA) have great potential for treatment of chronic osteomyelitis. However, PLGA has a glass-transition temperature that is higher than physiological temperatures, resulting in a lack of flexibility for implantation into the bone marrow cavity. As an alternative, poly(d, l-lactide-co-glycolide-co-ε-caprolactone) (PLGC) presents good flexibility due to the introduction of poly(ε-caprolactone) segments. To develop a new strategy for treatment of chronic osteomyelitis, a ciprofloxacin delivery system was prepared using PLGC as carriers, the antibacterial effects of which were evaluated both in vivo and in vitro. The in vitro release behavior showed that the average release reached 268.5 μg/days on day 33, with a cumulative release rate of 56.01%. A bacteriostatic ring, with a diameter of 26.83 ± 0.83 mm, was produced by ciprofloxacin against Staphylococcus aureus after 30 days of release via our ciprofloxacin-PLGC system. After 4 weeks of treatment in vivo, chronic-osteomyelitis-model rats had a bodyweight of 385.83 ± 17.23 g and a normal white-blood-cell count, as well as a lower number of bacterial colonies per gram of bone tissue of (10.6 ± 3.0) × 10¹ CFU/g. Furthermore, no inflammatory cells were observed via hematoxylin-and-eosin staining, and normal bone structure was observed via X-ray. Taken together, our findings indicate that our novel ciprofloxacin-PLGC system yielded noteworthy antibacterial effects both in vitro and in vivo, suggesting that it may be useful for treating patients with chronic osteomyelitis.

Recent advances in the formulation of PLGA microparticles for controlled drug delivery

Polymeric microparticles (MPs) are recognized as very popular carriers to increase the bioavailability and bio-distribution of both lipophilic and hydrophilic drugs. Among different kinds of polymers, poly-(lactic-co-glycolic acid) (PLGA) is one of the most accepted materials for this purpose, because of its biodegradability (due to the presence of ester linkages that are degraded by hydrolysis in aqueous environments) and safety (PLGA is a Food and Drug Administration (FDA)-approved compound). Moreover, its biodegradability depends on the number of glycolide units present in the structure, indeed, lower glycol content results in an increased degradation time and conversely a higher monomer unit number results in a decreased time. Due to this feature, it is possible to design and fabricate MPs with a programmable and time-controlled drug release. Many approaches and procedures can be used to prepare MPs. The chosen fabrication methodology influences size, stability, entrapment efficiency, and MPs release kinetics. For example, lipophilic drugs as chemotherapeutic agents (doxorubicin), anti-inflammatory non-steroidal (indomethacin), and nutraceuticals (curcumin) were successfully encapsulated in MPs prepared by single emulsion technique, while water-soluble compounds, such as aptamer, peptides and proteins, involved the use of double emulsion systems to provide a hydrophilic compartment and prevent molecular degradation. The purpose of this review is to provide an overview about the preparation and characterization of drug-loaded PLGA MPs obtained by single, double emulsion and microfluidic techniques, and their current applications in the pharmaceutical industry.Graphic abstract.

Progress and Prospects of Polymer-Based Drug Delivery Systems for Bone Tissue Regeneration

Despite the high regenerative capacity of bone tissue, there are some cases where bone repair is insufficient for a complete functional and structural recovery after damage. Current surgical techniques utilize natural and synthetic bone grafts for bone healing, as well as collagen sponges loaded with drugs. However, there are certain disadvantages associated with these techniques in clinical usage. To improve the therapeutic efficacy of bone tissue regeneration, a number of drug delivery systems based on biodegradable natural and synthetic polymers were developed and examined in in vitro and in vivo studies. Recent studies have demonstrated that biodegradable polymers play a key role in the development of innovative drug delivery systems and tissue engineered constructs, which improve the treatment and regeneration of damaged bone tissue. In this review, we discuss the most recent advances in the field of polymer-based drug delivery systems for the promotion of bone tissue regeneration and the physical-chemical modifications of polymers for controlled and sustained release of one or more drugs. In addition, special attention is given to recent developments on polymer nano- and microparticle-based drug delivery systems for bone regeneration.

The Role of NIR Fluorescence in MDR Cancer Treatment: From Targeted Imaging to Phototherapy

BACKGROUND

Multidrug Resistance (MDR) is defined as a cross-resistance of cancer cells to various chemotherapeutics and has been demonstrated to correlate with drug efflux pumps. Visualization of drug efflux pumps is useful to pre-select patients who may be insensitive to chemotherapy, thus preventing patients from unnecessary treatment. Near-Infrared (NIR) imaging is an attractive approach to monitoring MDR due to its low tissue autofluorescence and deep tissue penetration. Molecular NIR imaging of MDR cancers requires stable probes targeting biomarkers with high specificity and affinity.

OBJECTIVE

This article aims to provide a concise review of novel NIR probes and their applications in MDR cancer treatment.

RESULTS

Recently, extensive research has been performed to develop novel NIR probes and several strategies display great promise. These strategies include chemical conjugation between NIR dyes and ligands targeting MDR-associated biomarkers, native NIR dyes with inherent targeting ability, activatable NIR probes as well as NIR dyes loaded nanoparticles. Moreover, NIR probes have been widely employed for photothermal and photodynamic therapy in cancer treatment, which combine with other modalities to overcome MDR. With the rapid advancing of nanotechnology, various nanoparticles are incorporated with NIR dyes to provide multifunctional platforms for controlled drug delivery and combined therapy to combat MDR. The construction of these probes for MDR cancers targeted NIR imaging and phototherapy will be discussed. Multimodal nanoscale platform which integrates MDR monitoring and combined therapy will also be encompassed.

CONCLUSION

We believe these NIR probes project a promising approach for diagnosis and therapy of MDR cancers, thus holding great potential to reach clinical settings in cancer treatment.

Advances and clinical challenges for translating nerve conduit technology from bench to bed side for peripheral nerve repair

Injuries to the peripheral nervous system remain a large-scale clinical problem. These injuries often lead to loss of motor and/or sensory function that significantly affects patients' quality of life. The current neurosurgical approach for peripheral nerve repair involves autologous nerve transplantation, which often leads to clinical complications. The most pressing need is to increase the regenerative capacity of existing tubular constructs in the repair of large nerve gaps through development of tissue-engineered approaches that can surpass the performance of autografts. To fully realize the clinical potential of nerve conduit technology, there is a need to reconsider design strategies, biomaterial selection, fabrication techniques and the various potential modifications to optimize a conduit microenvironment that can best mimic the natural process of regeneration. In recent years, a significant progress has been made in the designing and functionality of bioengineered nerve conduits to bridge long peripheral nerve gaps in various animal models. However, translation of this work from lab to commercial scale has not been achieve. The current review summarizes recent advances in the development of tissue engineered nerve guidance conduits (NGCs) with regard to choice of material, novel fabrication methods, surface modifications and regenerative cues such as stem cells and growth factors to improve regeneration performance. Also, the current clinical potential and future perspectives to achieve therapeutic benefits of NGCs will be discussed in context of peripheral nerve regeneration.

An outlook on procedures of conjugating folate to (co)polymers and drugs for effective cancer targeting

Folate receptors (FRs) are expressed in vast majority of cancers. Selective targeting of the FRs is, therefore, one of the most popular and sought-after strategies for improving the efficacy of cancer therapeutics. Variety of approaches involving folate conjugation to several well-known and novel, nontoxic, biodegradable, and biocompatible (co)polymers have been attempted and successfully applied to a large number of nanoparticulate drug delivery systems (micelles, liposomes, nanoparticles, quantum dots, mesoporous silica-based materials, and others) in the last decade-and-a-half. Standard and novel synthetic approaches were utilized for the conjugation, followed by the formulation of the drug delivery modality. In most of the cases, the targeted system lived up to its reputation, validating its usefulness in targeted cancer therapeutics. The present review summarizes the progress and state-of-the-art synthetic methodologies for folate conjugation to (co)polymers, drugs, and nucleic acids. The limitations of the FR targeting are discussed in brief to give the reader the other side of the story. Finally, the information on marketed folic acid conjugates highlight their industrial applications.

An Overview on Spray-Drying of Protein-Loaded Polymeric Nanoparticles for Dry Powder Inhalation

The delivery of therapeutic proteins remains a challenge, despite recent technological advances. While the delivery of proteins to the lungs is the gold standard for topical and systemic therapy through the lungs, the issue still exists. While pulmonary delivery is highly attractive due to its non-invasive nature, large surface area, possibility of topical and systemic administration, and rapid absorption circumventing the first-pass effect, the absorption of therapeutic proteins is still ineffective, largely due to the immunological and physicochemical barriers of the lungs. Most studies using spray-drying for the nanoencapsulation of drugs focus on the delivery of conventional drugs, which are less susceptible to bioactivity loss, compared to proteins. Herein, the development of polymeric nanoparticles by spray-drying for the delivery of therapeutic proteins is reviewed with an emphasis on its advantages and challenges, and the techniques to evaluate their in vitro and in vivo performance. The protein stability within the carrier and the features of the carrier are properly addressed.

Improving cellular uptake and cytotoxicity of chitosan-coated poly(lactic-co-glycolic acid) nanoparticles in macrophages

Aim: This research aims to identify important formulation parameters for the enhancement of nanoparticle (NP) uptake and decreasing the cytotoxicity in macrophages. Materials & methods: Fluorescent poly(lactic-co-glycolic acid) (PLGA) nanocarriers were characterized for size distributions, zeta potential and encapsulation efficiency. Incubation time, size class, PLGA derivative and chitosan derivative were assessed for uptake kinetics and cell viability. Results: The major determining factor for enhancing cellular uptake were chitosan coatings, combined with acid-terminated PLGA and small NP size. Moreover, cytotoxicity was more favorable for small, chitosan glutamate-coated, acid-terminated PLGA NPs compared with its plain chitosan-coated counterparts. Conclusion: Chitosan glutamate has been shown to be a valuable alternative coating material for acid-terminated PLGA NPs to efficiently and safely target macrophages.

Dimethyloxallyl glycine/nanosilicates-loaded osteogenic/angiogenic difunctional fibrous structure for functional periodontal tissue regeneration

The coupled process of osteogenesis-angiogenesis plays a crucial role in periodontal tissue regeneration. Although various cytokines or chemokines have been widely applied in periodontal in situ tissue engineering, most of them are macromolecular proteins with the drawbacks of short effective half-life, poor stability and high cost, which constrain their clinical translation. Our study aimed to develop a difunctional structure for periodontal tissue regeneration by incorporating an angiogenic small molecule, dimethyloxalylglycine (DMOG), and an osteoinductive inorganic nanomaterial, nanosilicate (nSi) into poly (lactic-co-glycolic acid) (PLGA) fibers by electrospinning. The physiochemical properties of DMOG/nSi-PLGA fibrous membranes were characterized. Thereafter, the effect of DMOG/nSi-PLGA membranes on periodontal tissue regeneration was evaluated by detecting osteogenic and angiogenic differentiation potential of periodontal ligament stem cells (PDLSCs) in vitro. Additionally, the fibrous membranes were transplanted into rat periodontal defects, and tissue regeneration was assessed with histological evaluation, micro-computed tomography (micro-CT), and immunohistochemical analysis. DMOG/nSi-PLGA membranes possessed preferable mechanical property and biocompatibility. PDLSCs seeded on the DMOG/nSi-PLGA membranes showed up-regulated expression of osteogenic and angiogenic markers, higher alkaline phosphatase (ALP) activity, and more tube formation in comparison with single application. Further, in vivo study showed that the DMOG/nSi-PLGA membranes promoted recruitment of CD90+/CD34− stromal cells, induced angiogenesis and osteogenesis, and regenerated cementum-ligament-bone complex in periodontal defects. Consequently, the combination of DMOG and nSi exerted admirable effects on periodontal tissue regeneration. DMOG/nSi-PLGA fibrous membranes could enhance and orchestrate osteogenesis-angiogenesis, and may have the potential to be translated as an effective scaffold in periodontal tissue engineering.

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Dual-load fibrous structure possessed preferable mechanical property and biocompatibility.

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Fibrous structure can orchestrate and enhance osteogenesis-angiogenesis coupling.

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Difunctional fibrous structure can recruit CD90+/CD34− stromal cells to periodontal defects.

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Difunctional fibrous structure obtained functional periodontal tissue regeneration.

Prolonged Plasma Exposure of the Kv1.3-Inhibitory Peptide HsTX1[R14A] by Subcutaneous Administration of a Poly(Lactic-co-Glycolic Acid) (PLGA) Microsphere Formulation

This study evaluated the impact of poly(lactic-co-glycolic acid) (PLGA) microsphere formulations on in vitro release and in vivo plasma exposure of HsTX1[R14A], a potent inhibitor of the voltage-gated potassium channel Kv1.3, with potential to treat autoimmune conditions. Microspheres containing HsTX1[R14A] were prepared using different PLGA materials, including Resomer® RG502H, RG503H and PURASORB® PDLG 5004 (Purac). After assessing encapsulation efficiency and in vitro release, plasma concentrations of HsTX1[R14A] were quantified by LCMS/MS following subcutaneous administration of HsTX1[R14A]-loaded RG503H microspheres (15 mg/kg) or HsTX1[R14A] solution (4 mg/kg) to Sprague-Dawley rats. Microspheres prepared with Purac exhibited the greatest encapsulation efficiency (45.5 ± 2.4% (mean ± SD)) and RG502H the lowest (22.0 ± 6.4%). Release of HsTX1[R14A] was fastest in vitro for RG502H microspheres (maximum release at 31 days) and slowest for Purac (82 days). With a relatively rapid burst release of 20.0 ± 0.4% and a controlled release profile of up to 41 days, HsTX1[R14A]-loaded RG503H microspheres were selected for subcutaneous administration, resulting in detectable plasma concentrations for 11 days relative to 8 h following subcutaneous administration of HsTX1[R14A] solution. Therefore, subcutaneous administration of RG503H PLGA microspheres is a promising approach to be exploited for delivery of this immune modulator.

MAGE-Targeted Gold Nanoparticles for Ultrasound Imaging-Guided Phototherapy in Melanoma

Gold nanorods exhibit a wide variety of applications such as tumor molecular imaging and photothermal therapy (PTT) due to their tunable optical properties. Several studies have demonstrated that the combination of other therapeutic strategies may improve PTT efficiency. A method called optical droplet vaporization (ODV) was considered as another noninvasive imaging and therapy strategy. Via the ODV method, superheated perfluorocarbon droplets can be vaporized to a gas phase for enhancing ultrasound imaging; meanwhile, this violent process can cause damage to cells and tissue. In addition, active targeting through the functionalization with targeting ligands can effectively increase nanoprobe accumulation in the tumor area, improving the sensitivity and specificity of imaging and therapy. Our study prepared a nanoparticle loaded with gold nanorods and perfluorinated hexane and conjugated to a monoclonal antibody (MAGE-1 antibody) to melanoma-associated antigens (MAGE) targeting melanoma, investigated the synergistic effect of PTT/ODV therapy, and monitored the therapeutic effect using ultrasound. The prepared MAGE-Au-PFH-NPs achieved complete eradication of tumors. Meanwhile, the MAGE-Au-PFH-NPs also possess significant ultrasound imaging signal enhancement, which shows the potential for imaging-guided tumor therapy in the future.

Anti-CD206 antibody-conjugated Fe3O4-based PLGA nanoparticles selectively promote tumor-associated macrophages to polarize to the pro-inflammatory subtype

M2 macrophages serve roles in inhibiting inflammation and promoting tumor development. Reversing tumor-associated macrophages (TAMs) from M2- to M1-type polarization may provide an important strategy for tumor immunotherapy. The present study aimed to enhance antitumor immunity by targeting the concentration of iron in macrophages. Fe₃O₄-based poly(lactic-co-glycolic) acid (PLGA) nanoparticles surface-modified with an anti-CD206 monoclonal antibody were prepared using the oil in water single-emulsion technique. Particle size was measured using a particle size analyzer, the ζ potential was determined using a ζ potential analyzer and the carrier rate of Fe₃O₄ was measured using an iron assay kit. The conjugation of anti-CD206, and the ability to target M2 macrophages were studied via immunofluorescence. Polarization indexes of the macrophages were detected using both western blotting and reverse transcription-quantitative PCR (RT-qPCR), and a mouse model with subcutaneous tumors was established to verify the antitumor effects of the nanoparticles in vivo. Nanoparticles had a mean diameter in the range of 260–295 nm, and the ζ potential values were between −19 and −33 mV. The Fe₃O₄ association efficiency ranged from 65–75%, whereas the anti-CD206 conjunction efficiency ranged from 65–70%. The immunofluorescence experiments were able to demonstrate the successful targeting of the M2 macrophages. The western blotting and RT-qPCR experiments identified that CD206-Fe₃O₄-PLGA and Fe₃O₄-PLGA promoted the expression of TNF-α, inducible nitric oxide synthase (iNOS) and IL-1β in the macrophages. The in vivo studies indicated that CD206-Fe₃O₄-PLGA nanoparticles were able to promote CD86 expression in TAMs, with CD86 being a specific marker of the M1 subtype. In summary, nanoparticles were characterized in the present study by their mean particle size, polydispersity index, ζ potential and morphology, as well as by their association with Fe₃O₄ and conjugation with the anti-CD206 monoclonal antibody. Collectively, the present results suggested that the nanoparticles were able to both target M2 macrophages and reverse the M2 polarization of the macrophages to the M1 phenotype via the release of coated iron-oxide particles.

Shear Speed-Regulated Properties of Long-Acting Docetaxel Control Release Poly (Lactic-Co-Glycolic Acid) Microspheres

Advanced drug carriers for the controlled release of chemotherapeutics in the treatment of malignant tumors have drawn significant notice in recent years. In the current study, microspheres (MPs) loaded with docetaxel (DTX) were prepared using polylactic-co-glycolic acid copolymer (PLGA). The double emulsion solvent evaporation method is simple to perform, and results in high encapsulation efficiency. Electron micrographs of the MPs showed that controlling the shear rate can effectively control the size of the MPs. At present, most DTX sustained-release carriers cannot maintain stable and long-term local drug release. The 1.68 μm DTX-loaded microspheres (MP/DTX) with elastase was completely degraded in 14 d. This controlled degradation period is similar to a course of treatment for most cancers. The drug release profile of all kinds of MP/DTX demonstrated an initial rapid release, then slower and stable release to the end. The current study demonstrates that it is possible to create drug-loaded MPs with specific degradation times and drug release curves, which may be useful in achieving optimal treatment times and drug release rates for different diseases, and different drug delivery routes. The initial burst release reaches the effective concentration of the drug at the beginning of release, and then the drug concentration is maintained by stable release to reduce the number of injections and improve patient compliance.

Just how prevalent are peptide therapeutic products? A critical review

How prevalent are peptide therapeutic products? How innovative are the formulations used to deliver peptides? This review provides a critical analysis of therapeutic peptide products and the formulations approved by the United States Food and Drug administration (FDA), the European Medicines Agency (EMA), and the Japanese Pharmaceuticals and Medical Devices Agency (PMDA). This review also provides an in-depth analysis of dosage forms and administration routes for delivering peptide therapeutics, including injectables, oral dosage forms, and other routes of administration. We discuss the function of excipients in parenteral formulations in detail, since most peptide therapeutics are parenterally administered. We provide case studies of alternate delivery routes and dosage forms. Based on our analysis, therapeutic peptides administered as injectables remain the most commonly used dosage forms, particularly in the form of subcutaneous, intravenous, or intramuscular injections. In addition, therapeutic peptides are formulated to achieve prolonged release, often through the use of polymer carriers. The limited number of oral therapeutic peptide products and their poor absorption and subsequent low bioavailability indicate a need for new technologies to broaden the formulation design space. Therapeutic peptide products may also be delivered through other administration routes, including intranasal, implant, and sublingual routes. Therefore, an in-depth understanding of how therapeutic peptides are now formulated and administered is essential to improve peptide delivery, improve patient compliance, and reduce the healthcare burden for these crucial therapeutic agents.

Advanced polymeric nanotechnology to augment therapeutic delivery and disease diagnosis

Therapeutic and diagnostic payloads are usually associated with properties that compromise their efficacy, such as poor aqueous solubility, short half-life, low bioavailability, nonspecific accumulation and diverse side effects. Nanotechnological solutions have emerged to circumvent some of these drawbacks, augmenting therapeutic and/or diagnostic outcomes. Nanotechnology has benefited from the rise in polymer science research for the development of novel nanosystems for therapeutic and diagnostic purposes. Polymers are a widely used class of biomaterials, with a considerable number of regulatory approvals for application in clinics. In addition to their versatility in production and functionalization, several synthetic and natural polymers demonstrate biocompatible properties that dictate their successful biological performance. This article highlights the physicochemical characteristics of a variety of natural and synthetic biocompatible polymers, as well as their role in the manufacture of nanotechnology-based systems, state-of-art applications in disease treatment and diagnosis, and current challenges in finding a way to clinics.

Biodegradable Electrospun Nonwovens Releasing Propolis as a Promising Dressing Material for Burn Wound Treatment

The selection of dressing is crucial for the wound healing process. Traditional dressings protect against contamination and mechanical damage of an injured tissue. Alternatives for standard dressings are regenerating systems containing a polymer with an incorporated active compound. The aim of this research was to obtain a biodegradable wound dressing releasing propolis in a controlled manner throughout the healing process. Dressings were obtained by electrospinning a poly(lactide-co-glycolide) copolymer (PLGA) and propolis solution. The experiment consisted of in vitro drug release studies and in vivo macroscopic treatment evaluation. In in vitro studies released active compounds, the morphology of nonwovens, chemical composition changes of polymeric material during degradation process, weight loss and water absorption were determined. For in vivo research, four domestic pigs, were used. The 21-day experiment consisted of observation of healing third-degree burn wounds supplied with PLGA 85/15 nonwovens without active compound, with 5 wt % and 10 wt % of propolis, and wounds rinsed with NaCl. The in vitro experiment showed that controlling the molar ratio of lactidyl to glycolidyl units in the PLGA copolymer gives the opportunity to change the release profile of propolis from the nonwoven. The in vivo research showed that PLGA nonwovens with propolis may be a promising dressing material in the treatment of severe burn wounds.

Simvastatin enhanced antimicrobial effect of Ag+ against E. faecalis infection of dentine through PLGA co-delivery submicron particles

Enterococcus faecalis (E. faecalis) is one of the dominant bacteria for refractory infections of teeth. Silver ions (Ag⁺) have been proved to be a strong bactericide but with high cytotoxicity and discoloration property. Simvastatin is an agent used for dyslipidemia treatment and has anti-inflammatory property. In this study, Ag⁺ and simvastatin were for the first time used in combination, and poly (lactide-co-glycolide) (PLGA) submicron particles carrying both Ag⁺ and simvastatin (AgS-PLGA) were fabricated for further investigations. Results confirmed the enhanced antibacterial activity against E. faecalis of Ag⁺ by simvastatin. AgS-PLGA could release both Ag⁺ and simvastatin for 24 days and also showed enhanced antibacterial activities. On dentin slices, AgS-PLGA could enter dentinal tubules by ultrasonic activation and inhibit the colonization of E. faecalis. AgS-PLGA showed no cytotoxicity on MC3T3-E1 cells and slight suppressive effect on RAW-264.7 cells, and could reduce the secretion of IL-6 and IL-1β of RAW-264.7 cells. AgS-PLGA could be developed as a new biomaterial for infection and inflammation control for dental and related medical treatments.

Antioxidant-mediated control of degradation and drug release from surface-eroding poly(ethylene carbonate)

Surface-eroding polymers are of significant interest for various applications in the field of controlled drug delivery. Poly(ethylene carbonate), as an example, offers little control over the rate of degradation and, thus, drug release, which usually conflicts with the requirements for long-acting medications. Here, we challenged an option to decelerate the degradation of poly(ethylene carbonate) in vitro and in vivo. When polymer films loaded with distinct antioxidants (vitamins) along with the model drugs leuprorelin and risperidone were incubated in superoxide radical solution and phagocyte culture, the mass loss and drug release from the delivery vehicle was a function of the type and dose of the utilized antioxidant. Once the polymer surface was "attacked" by reactive oxygen species, the antioxidants were released on demand quenching the polymer-degrading radicals. Accordingly, specific combinations of polymer and radical scavengers resulted in controlled release medications with an extended "life-time" of one month or longer, which is difficult to achieve for poly(ethylene carbonate) in the absence of antioxidants. A comparable degradation and drug release behavior was observed when antioxidant-loaded poly(ethylene carbonate) films were implanted in rats. Furthermore, linear correlations were obtained between the mass loss of the polymer films and the released fraction of drug (with slopes close to 1), a clear indication for the surface erosion of poly(ethylene carbonate) in vitro and in vivo. Overall, an addition of antioxidants to poly(ethylene carbonate)-based controlled drug delivery vehicles represents a reasonable approach to modify the performance of long-acting medications, especially when a "life time" of weeks to months needs to be achieved. STATEMENT OF SIGNIFICANCE: Surface-eroding poly(ethylene carbonate) (PEC) is of significant interest for long-acting injectable formulations. However, PEC offers only little control over the rate of degradation and, thus, drug release kinetics. We describe an option to decelerate the degradation rate of PEC in vitro and in vivo. When polymer films loaded with distinct antioxidants along with model drugs were incubated in superoxide radical solution, phagocyte culture and implanted in rats, their mass loss and drug release was a function of the type and dose of the utilized antioxidant. Accordingly, specific combinations of polymer and radical scavengers resulted in controlled release medications with an extended "life-time" of one month or longer, which is difficult to achieve for PEC in the absence of antioxidants.

3D printed intelligent scaffold prevents recurrence and distal metastasis of breast cancer

Rationale: Tumors are commonly treated by resection, which usually leads to massive hemorrhage and tumor cell residues, thereby increasing the risk of local recurrence and distant metastasis.

Methods: Herein, an intelligent 3D-printed poly(lactic-co-glycolic acid), gelatin, and chitosan scaffold loaded with anti-cancer drugs was prepared that showed hemostatic function and good pH sensitivity.

Results: Following in situ implantation in wounds, the scaffolds absorbed hemorrhage and cell residues after surgery, and promoted wound healing. In an in vivo environment, the scaffold responded to the slightly acidic environment of the tumor to undergo sustained drug release to significantly inhibit the recurrence and growth of the tumor, and reduced drug toxicity, all without causing damage to healthy tissues and with good biocompatibility.

Conclusions: The multifunctional intelligent scaffold represents an excellent treatment modality for breast cancer following resection, and provides great potential for efficient cancer therapy.

Efficient Delivery of Transducing Polymer Nanoparticles for Gene-Mediated Induction of Osteogenesis for Bone Regeneration

Developing non-viral gene therapy vectors that both protect and functionally deliver nucleic acid cargoes will be vital if gene augmentation and editing strategies are to be effectively combined with advanced regenerative medicine approaches. Currently such methodologies utilize high concentrations of recombinant growth factors, which result in toxicity and off-target effects. Herein we demonstrate the use of modified cell penetrating peptides (CPPs), termed Glycosaminoglycan (GAG)-binding Enhanced Transduction (GET) peptides with plasmid DNA (pDNA) encapsulated poly (lactic-co-glycolic acid) PLGA nanoparticles (pDNA-encapsulated PLGA NPs). In order to encapsulate the pDNA, it was first condensed with a cationic low molecular weight Poly L-Lysine (PLL) into 30-60 nm NPs followed by encapsulation in PLGA NPs by double emulsion; yielding encapsulation efficiencies (EE) of ∼30%. PLGA NPs complexed with GET peptides show enhanced intracellular delivery (up to sevenfold) and transfection efficiencies (up to five orders of magnitude). Moreover, the pDNA cargo has enhanced protection from nucleases (such as DNase I) promoting their translatability. As an example, we show these NPs efficiently deliver pBMP2 which can promote osteogenic differentiation in vitro. Gene delivery to human Mesenchymal Stromal Cells (hMSCs) inducing their osteogenic programming was confirmed by Alizarin red calcium staining and bone lineage specific gene expression (Q RT-PCR). By combining simplistic and FDA-approved PLGA polymer nanotechnology with the GET delivery system, therapeutic non-viral vectors could have significant impact in future cellular therapy and regenerative medicine applications.

In Situ Forming Injectable Thermoresponsive Hydrogels for Controlled Delivery of Biomacromolecules

Due to their relatively large molecular sizes and delicate nature, biologic drugs such as peptides, proteins, and antibodies often require high and repeated dosing, which can cause undesired side effects and physical discomfort in patients and render many therapies inordinately expensive. To enhance the efficacy of biologic drugs, they could be encapsulated into polymeric hydrogel formulations to preserve their stability and help tune their release in the body to their most favorable profile of action for a given therapy. In this study, a series of injectable, thermoresponsive hydrogel formulations were evaluated as controlled delivery systems for various peptides and proteins, including insulin, Merck proprietary peptides (glucagon-like peptide analogue and modified insulin analogue), bovine serum albumin, and immunoglobulin G. These hydrogels were prepared using concentrated solutions of poly(lactide-co-glycolide)-block-poly(ethylene glycol)-block-poly(lactide-co-glycolide) (PLGA-PEG-PLGA), which can undergo temperature-induced sol-gel transitions and spontaneously solidify into hydrogels near the body temperature, serving as an in situ depot for sustained drug release. The thermoresponsiveness and gelation properties of these triblock copolymers were characterized by dynamic light scattering (DLS) and oscillatory rheology, respectively. The impact of different hydrogel-forming polymers on release kinetics was systematically investigated based on their hydrophobicity (LA/GA ratios), polymer concentrations (20, 25, and 30%), and phase stability. These hydrogels were able to release active peptides and proteins in a controlled manner from 4 to 35 days, depending on the polymer concentration, solubility nature, and molecular sizes of the cargoes. Biophysical studies via size exclusion chromatography (SEC) and circular dichroism (CD) indicated that the encapsulation and release did not adversely affect the protein conformation and stability. Finally, a selected PLGA-PEG-PLGA hydrogel system was further investigated by the encapsulation of a therapeutic glucagon-like peptide analogue and a modified insulin peptide analogue in diabetic mouse and minipig models for studies of glucose-lowering efficacy and pharmacokinetics, where superior sustained peptide release profiles and long-lasting glucose-lowering effects were observed in vivo without any significant tolerability issues compared to peptide solution controls. These results suggest the promise of developing injectable thermoresponsive hydrogel formulations for the tunable release of protein therapeutics to improve patient's comfort, convenience, and compliance.

Fabrication and Plasma Surface Activation of Aligned Electrospun PLGA Fiber Fleeces with Improved Adhesion and Infiltration of Amniotic Epithelial Stem Cells Maintaining their Teno-inductive Potential

Electrospun PLGA microfibers with adequate intrinsic physical features (fiber alignment and diameter) have been shown to boost teno-differentiation and may represent a promising solution for tendon tissue engineering. However, the hydrophobic properties of PLGA may be adjusted through specific treatments to improve cell biodisponibility. In this study, electrospun PLGA with highly aligned microfibers were cold atmospheric plasma (CAP)-treated by varying the treatment exposure time (30, 60, and 90 s) and the working distance (1.3 and 1.7 cm) and characterized by their physicochemical, mechanical and bioactive properties on ovine amniotic epithelial cells (oAECs). CAP improved the hydrophilic properties of the treated materials due to the incorporation of new oxygen polar functionalities on the microfibers' surface especially when increasing treatment exposure time and lowering working distance. The mechanical properties, though, were affected by the treatment exposure time where the optimum performance was obtained after 60 s. Furthermore, CAP treatment did not alter oAECs' biocompatibility and improved cell adhesion and infiltration onto the microfibers especially those treated from a distance of 1.3 cm. Moreover, teno-inductive potential of highly aligned PLGA electrospun microfibers was maintained. Indeed, cells cultured onto the untreated and CAP treated microfibers differentiated towards the tenogenic lineage expressing tenomodulin, a mature tendon marker, in their cytoplasm. In conclusion, CAP treatment on PLGA microfibers conducted at 1.3 cm working distance represent the optimum conditions to activate PLGA surface by improving their hydrophilicity and cell bio-responsiveness. Since for tendon tissue engineering purposes, both high cell adhesion and mechanical parameters are crucial, PLGA treated for 60 s at 1.3 cm was identified as the optimal construct.

Polymeric vehicles for nucleic acid delivery

Polymeric vehicles are versatile tools for therapeutic gene delivery. Many polymers-when assembled with nucleic acids into vehicles-can protect the cargo from degradation and clearance in vivo, and facilitate its transport into intracellular compartments. Design options in polymer synthesis yield a comprehensive range of molecules and resulting vehicle formulations. These properties can be manipulated to achieve stronger association with nucleic acid cargo and cells, improved endosomal escape, or sustained delivery depending on the application. Here, we describe current approaches for polymer use and related strategies for gene delivery in preclinical and clinical applications. Polymer vehicles delivering genetic material have already achieved significant therapeutic endpoints in vitro and in animal models. From our perspective, with preclincal assays that better mimic the in vivo environment, improved strategies for target specificity, and scalable techniques for polymer synthesis, the impact of this therapeutic approach will continue to expand.

The Stabilizing Excipients in Dry State Therapeutic Phage Formulations

Phage therapy has gained prominence due to the increasing pathogenicity of "super bugs" and the rise of their multidrug resistance to conventional antibiotics. Dry state formulation of therapeutic phage is attractive to improve their "druggability" by increasing their shelf life, improving their ease of handling, and ultimately retaining their long-term potency. The use and selection of excipients are critical to stabilize phage in solid formulations and protect their viability from stresses encountered during the solidification process and long-term storage prior to use. Here, this review focuses on the current classes of excipients used to manufacture dry state phage formulations and their ability to stabilize and protect phage throughout the process, as discussed in the literature. We provide perspective of outstanding challenges involved in the formulation of dry state phage. We suggest strategies to improve excipient identification and selection, optimize the potential excipient combinations to improve phage viability during formulation, and evaluate new methodologies that can provide greater insight into phage-excipient interactions to improve design criteria to improve formulation of dry state phage therapeutics. Addressing these challenges opens up new opportunities to re-design and re-imagine phage formulations for improved efficacy as a pharmaceutical product.

Neuron tau-targeting biomimetic nanoparticles for curcumin delivery to delay progression of Alzheimer's disease

BACKGROUND

Although many therapeutic strategies for Alzheimer's disease (AD) have been explored, these strategies are seldom used in the clinic. Therefore, AD therapeutic research is still urgently needed. One major challenge in the field of nanotherapeutics is to increase the selective delivery of drugs to a targeted location. Herein, we devised and tested a strategy for delivery of nanoparticles to neurons to inhibit tau aggregation by directly targeting p-tau.

RESULTS

Curcumin (CUR) is loaded onto red blood cell (RBC) membrane-coated PLGA particles bearing T807 molecules attached to the RBC membrane surface (T807/RPCNP). With the advantage of the suitable physicochemical properties of the PLGA nanoparticles and the unique biological functions of the RBC membrane, the RPCNP are stabilized and promote sustained CUR release, which provided improved biocompatibility and resulted in long-term presence in the circulation. Under the synergistic effects of T807, T807/RPCNP can not only effectively penetrate the blood-brain barrier (BBB), but they also possess high binding affinity to hyperphosphorylated tau in nerve cells where they inhibit multiple key pathways in tau-associated AD pathogenesis. When CUR was encapsulated, our data also demonstrated that CUR-loaded T807/RPCNP NPs can relieve AD symptoms by reducing p-tau levels and suppressing neuronal-like cells death both in vitro and in vivo. The memory impairment observed in an AD mouse model is significantly improved following systemic administration of CUR-loaded T807/RPCNP NPs.

CONCLUSION

Intravenous neuronal tau-targeted T807-modified novel biomimetic nanosystems are a promising clinical candidate for the treatment of AD.

PLGA Nanoparticles for the Intraperitoneal Administration of CBD in the Treatment of Ovarian Cancer: In Vitro and In Ovo Assessment

The intraperitoneal administration of chemotherapeutics has emerged as a potential route in ovarian cancer treatment. Nanoparticles as carriers for these agents could be interesting by increasing the retention of chemotherapeutics within the peritoneal cavity. Moreover, nanoparticles could be internalised by cancer cells and let the drug release near the biological target, which could increase the anticancer efficacy. Cannabidiol (CBD), the main nonpsychotropic cannabinoid, appears as a potential anticancer drug. The aim of this work was to develop polymer nanoparticles as CBD carriers capable of being internalised by ovarian cancer cells. The drug-loaded nanoparticles (CBD-NPs) exhibited a spherical shape, a particle size around 240 nm and a negative zeta potential (-16.6 ± 1.2 mV). The encapsulation efficiency was high, with values above 95%. A controlled CBD release for 96 h was achieved. Nanoparticle internalisation in SKOV-3 epithelial ovarian cancer cells mainly occurred between 2 and 4 h of incubation. CBD antiproliferative activity in ovarian cancer cells was preserved after encapsulation. In fact, CBD-NPs showed a lower IC₅₀ values than CBD in solution. Both CBD in solution and CBD-NPs induced the expression of PARP, indicating the onset of apoptosis. In SKOV-3-derived tumours formed in the chick embryo model, a slightly higher-although not statistically significant-tumour growth inhibition was observed with CBD-NPs compared to CBD in solution. To sum up, poly-lactic-co-glycolic acid (PLGA) nanoparticles could be a good strategy to deliver CBD intraperitoneally for ovarian cancer treatment.

Lignin-Graft-Poly(lactic-co-glycolic) Acid Biopolymers for Polymeric Nanoparticle Synthesis

A lignin-graft-poly(lactic-co-glycolic) acid (PLGA) biopolymer was synthesized with two types of lignin (LGN), alkaline lignin (ALGN) and sodium lignosulfonate (SLGN), at different (A/S)LGN/PLGA ratios (1:2, 1:4, and 1:6 w/w). 1H NMR and Fourier-transform infrared spectroscopy (FT-IR) confirmed the conjugation of PLGA to LGN. The (A/S)LGN-graft-PLGA biopolymers were used to form nanodelivery systems suitable for entrapment and delivery of drugs for disease treatment. The LGN-graft-PLGA NPs were generally small (100-200 nm), increased in size with the amount of PLGA added, monodisperse, and negatively charged (-48 to -60 mV). Small-angle scattering data showed that particles feature a relatively smooth surface and a compact spherical structure with a distinct core and a shell. The core size and shell thickness varied with the LGN/PLGA ratio, and at a 1:6 ratio, the particles deviated from the core-shell structure to a complex internal structure. The newly developed (A/S)LGN-graft-PLGA NPs are proposed as a potential delivery system for applications in biopharmaceutical, food, and agricultural sectors.

Physico-chemical and biological evaluation of doxycycline loaded into hybrid oxide-polymer layer on Ti-Mo alloy

Oxide-polymer coatings were formed on the surface of the vanadium-free Ti–15Mo titanium alloy. The Ti alloy surface was modified by the plasma electrolytic oxidation process, and then, the polymer layer of a poly (D, l-lactide-co-glycolide) with doxycycline was formed. The polymer evenly covered the porous oxide layer and filled some of the pores. However, the microstructure of the polymer surface was completely different from that of the PEO layer. The surface morphology, roughness and microstructure of the polymer layer were examined by scanning electron microscopy (SEM) and a confocal microscope. The results confirmed the effectiveness of polymer and doxycycline deposition in their stable chemical forms. The drug analysis was performed by high-performance liquid chromatography. The ¹H NMR technique was used to monitor the course of hydrolytic degradation of PLGA. It was shown that the PLGA layer is hydrolysed within a few weeks, and the polyglycolidyl part of the copolymer is hydrolysed to glycolic acid as first and much faster than the polylactide one to lactic acid. This paper presents influence of different microstructures on the biological properties of modified titanium alloys. Cytocompatibility and bacterial adhesion tests were evaluated using osteoblast-like MG-63 cells and using the reference S. aureus and S. epidermidis strains. The results showed that the optimum concentration of doxycycline was found to inhibit the growth of the bacteria and that the layer is still cytocompatible.

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Formation of the oxide-polymer layer containing doxycycline is presented.

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Changes in the doxycycline structure and the evaluation of their stability was analyzed using the HPLC.

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Thickness of the polymer layer was determined using the confocal microscopy.

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The coatings showed the antibacterial properties and were cytocompatible with osteoblast-ike MG-63 cells.

Icariin/Aspirin Composite Coating on TiO2 Nanotubes Surface Induce Immunomodulatory Effect of Macrophage and Improve Osteoblast Activity

Surface coating modification of titanium-based alloys is an efficient way to accelerate early osseointegration in dental implant fields. Icariin (ICA) is a traditional Chinese medicine that has bone activating functions, while aspirin (ASP) is a classical non-steroidal anti-inflammatory drug with good antipyretic and analgesic capabilities. Moreover, poly(lactic–co–glycolic acid) (PLGA) has attracted great attention due to its excellent biocompatibility and biodegradability. We superimposed an ASP/PLGA coating onto ICA loaded TiO2 nanotubes structure so as to establish an icariin/aspirin composite coating on TiO2 nanotubes surface. Scanning electron microscopy, X-ray photoelectron spectroscopy, a contact angle test and a drug release test confirmed the successful preparation of the NT–ICA–ASP/PLGA substrate, with a sustained release pattern of both ICA and ASP. Compared to those cultured on the Ti surface, macrophage cells on the NT-ICA-ASP/PLGA substrate displayed decreased M1 proinflammatory and enhanced M2 proregenerative genes and proteins expression, which implied activated immunomodulatory effect. Moreover, when cultured with conditioned medium from macrophages, osteoblast cells on the NT-ICA-ASP/PLGA substrate revealed improved cell proliferation, adhesion and osteogenic genes and proteins expression, compared with those on the Ti surface. The abovementioned results suggest that the established NT-ICA-ASP/PLGA substrate is a promising candidate for functionalized coating material in Ti implant surface modification.

Evaluation of apoptotic effects of mPEG-b-PLGA coated iron oxide nanoparticles as a eupatorin carrier on DU-145 and LNCaP human prostate cancer cell lines

Many studies have so far confirmed the efficiency of phytochemicals in the treatment of prostate cancer. Eupatorin, a flavonoid with a wide range of phytomedical activities, suppresses proliferation of and induces apoptosis of multiple cancer cell lines. However, low solubility, poor bioavailability, and rapid degradation limit its efficacy. The aim of our study was to evaluate whether the use of mPEG-b-poly (lactic-co-glycolic) acid (PLGA) coated iron oxide nanoparticles as a carrier could enhance the therapeutic efficacy of eupatorin in DU-145 and LNcaP human prostate cancer cell lines. Nanoparticles were prepared by the co-precipitation method and were fully characterized for morphology, surface charge, particle size, drug loading, encapsulation efficiency and in vitro drug-release profile. The inhibitory effect of nanoparticles on cell viability was evaluated by MTT test. Apoptosis was then determined by Hoechest staining, cell cycle analysis, NO production, annexin/propidium iodide (PI) assay, and Western blotting. The results indicated that eupatorin was successfully entrapped in Fe₃O₄@mPEG-b-PLGA nanoparticles with an efficacy of (90.99 ± 2.1)%. The nanoparticle’s size was around (58.5 ± 4) nm with a negative surface charge [(−34.16 ± 1.3) mV]. In vitro release investigation showed a 30% initial burst release of eupatorin in 24 h, followed by sustained release over 200 h. The MTT assay indicated that eupatorin-loaded Fe₃O₄@mPEG-b-PLGA nanoparticles exhibited a significant decrease in the growth rate of DU-145 and LNcaP cells and their IC50 concentrations were 100 μM and 75 μM, respectively. Next, apoptosis was confirmed by nuclear condensation, enhancement of cell population in the sub-G1 phase and increased NO level. Annexin/PI analysis demonstrated that eupatorin-loaded Fe₃O₄@mPEG-b-PLGA nanoparticles could increase apoptosis and decrease necrosis frequency. Finally, Western blotting analysis confirmed these results and showed that Bax/Bcl-2 ratio and the cleaved caspase-3 level were up-regulated by the designing nanoparticles. Encapsulation of eupatorin in Fe₃O₄@mPEG-b-PLGA nanoparticles increased its anticancer effects in prostate cancer cell lines as compared to free eupatorin. Based on these results, this formulation can provide a sustained eupatorin-delivery system for cancer treatment with the drug remaining active at a significantly lower dose, making it a suitable candidate for pharmacological uses.

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In the current study, Eupatorin was efficiently encapsulated in mPEG-b-PLGA coated iron oxide nanoparticles.

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The nanoparticles bypass the limitations and provide a sustained release of Eupatorin into the human prostate cancer cell.

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The designed nanoparticles can be more effective in inhibiting cancer cell growth as compared to free form.

Tunable Release of Curcumin with an In Silico-Supported Approach from Mixtures of Highly Porous PLGA Microparticles

In recent years, drug delivery systems have become some of the main topics within the biomedical field. In this scenario, polymeric microparticles (MPs) are often used as carriers to improve drug stability and drug pharmacokinetics in agreement with this kind of treatment. To avoid a mere and time-consuming empirical approach for the optimization of the pharmacokinetics of an MP-based formulation, here, we propose a simple predictive in silico-supported approach. As an example, in this study, we report the ability to predict and tune the release of curcumin (CUR), used as a model drug, from a designed combination of different poly(d,l-lactide-co-glycolide) (PLGA) MPs kinds. In detail, all CUR-PLGA MPs were synthesized by double emulsion technique and their chemical-physical properties were characterized by Mastersizer and scanning electron microscopy (SEM). Moreover, for all the MPs, CUR encapsulation efficiency and kinetic release were investigated through the UV-vis spectroscopy. This approach, based on the combination of in silico and experimental methods, could be a promising platform in several biomedical applications such as vaccinations, cancer-treatment, diabetes therapy and so on.

p66shc siRNA Nanoparticles Ameliorate Chondrocytic Mitochondrial Dysfunction in Osteoarthritis

Background

Osteoarthritis (OA) is the most common type of joint disease associated with cartilage breakdown. However, the role played by mitochondrial dysfunction in OA remains inadequately understood. Therefore, we investigated the role played by p66shc during oxidative damage and mitochondrial dysfunction in OA and the effects of p66shc downregulation on OA progression.

Methods

Monosodium iodoacetate (MIA), which is commonly used to generate OA animal models, inhibits glycolysis and biosynthetic processes in chondrocytes, eventually causing cell death. To observe the effects of MIA and poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles, histological analysis, immunohistochemistry, micro-CT, mechanical paw withdrawal thresholds, quantitative PCR, and measurement of oxygen consumption rate and extracellular acidification rate were conducted.

Results

p-p66shc was highly expressed in cartilage from OA patients and rats with MIA-induced OA. MIA caused mitochondrial dysfunction and reactive oxygen species (ROS) production, and the inhibition of p66shc phosphorylation attenuated MIA-induced ROS production in human chondrocytes. Inhibition of p66shc by PLGA-based nanoparticles-delivered siRNA ameliorated pain behavior, cartilage damage, and inflammatory cytokine production in the knee joints of MIA-induced OA rats.

Conclusion

p66shc is involved in cartilage degeneration in OA. By delivering p66shc-siRNA-loaded nanoparticles into the knee joints with OA, mitochondrial dysfunction-induced cartilage damage can be significantly decreased. Thus, p66shc siRNA PLGA nanoparticles may be a promising option for the treatment of OA.

Sonication tailored enhance cytotoxicity of naringenin nanoparticle in pancreatic cancer: design, optimization, and in vitro studies

Objective: In vitro, optimization, characterization, and cytotoxic studies of NAR nanoparticles (NPs) to against pancreatic cancer.Method: The sonication tailored Naringenin (NARG)-loaded poly (lactide-co-glycolic acid) (PLGA) NPs was fabricated for potential cytotoxic effect against pancreatic cancer. NARG NPs were prepared by emulsion-diffusion evaporation technique applying BoxBehnken experimental design based on three-level and three-factors. The effect of independent variables surfactant concentration (X₁), polymer concentration (X₂), and sonication time (X₃) were studied on responses particle size (Y₁), and drug release % (Y₂). NPs characterized for particles size and size distribution, polydispersity index (PDI), zeta potential, transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimeter (DSC), and X-ray diffraction (XRD) studies. Further, the studies was fitted to various drug release kinetic model and cytotoxicity evaluated in vitro.Results: The nanosized particles were spherical, uniform with an average size of 150.45 ± 12.45 nm, PDI value 0.132 ± 0.026, zeta potential -20.5 ± 2.5 mV, and cumulative percentage release 85.67 ± 6.23%. In vitro release of NARG from nanoparticle evaluated initially burst followed by sustained release behavior. The Higuchi was best fitted model to drug release from NARG NPs. The cytotoxicity study of NARG NPs apparently showed higher cytotoxic effect over free NARG (p < 0.05). The stability study of optimized formulation revealed no significant physico-chemical changes during 3 months.Conclusions: Thus, NARG-loaded NPs gave ameliorated anticancer effect over plain NARG.

Application of PLGA nano/microparticle delivery systems for immunomodulation and prevention of allotransplant rejection

INTRODUCTION

Allograft transplantation is an effective end-point therapy to replace the function of an impaired organ. The main problem associated with allotransplantation is the induction of immune responses that results in acute and chronic graft rejection. To modulate the response of the immune system, transplant recipients generally take high dose immunosuppressant drugs for life. These drugs are associated with serious side effects such as infection with opportunistic pathogens and the development of neoplasia.

AREAS COVERED

We reviewed the obstacles to successful transplantation and PLGA-based strategies to reduce immune-mediated allograft rejection.

EXPERT OPINION

Biomaterial-based approaches using micro- and nanoparticles such as poly (lactic-co-glycolic acid) (PLGA) can be used to achieve controlled release of drugs. This approach decreases the required effective dose of drugs and enables local delivery of these agents to specific tissues and cells, whilst decreasing systemic effects.