Preparation and in vivo evaluation of insulin-loaded biodegradable nanoparticles prepared from diblock copolymers of PLGA and PEG

Enhancing therapeutic efficacy: sustained delivery of 5-fluorouracil (5-FU) via thiolated chitosan nanoparticles targeting CD44 in triple-negative breast cancer

Our current study reports the successful synthesis of thiolated chitosan-based nanoparticles for targeted drug delivery of 5-Fluorouracil. This process was achieved through the ionic gelation technique, aiming to improve the efficacy of the chemotherapeutic moiety by modifying the surface of the nanoparticles (NPs) with a ligand. We coated these NPs with hyaluronic acid (HA) to actively target the CD44 receptor, which is frequently overexpressed in various solid malignancies, including breast cancer. XRD, FTIR, SEM, and TEM were used for the physicochemical analysis of the NPs. These 5-Fluorouracil (5-FU) loaded NPs were evaluated on MDA-MB-231 (a triple-negative breast cell line) and MCF-10A (normal epithelial breast cells) to determine their in vitro efficacy. The developed 5-FU-loaded NPs exhibited a particle size within a favorable range (< 300 nm). The positive zeta potential of these nanoparticles facilitated their uptake by negatively charged cancer cells. Moreover, they demonstrated robust stability and achieved high encapsulation efficiency. These nanoparticles exhibited significant cytotoxicity compared to the crude drug (p < 0.05) and displayed a promising release pattern consistent with the basic diffusion model. These traits improve the pharmacokinetic profile, efficacy, and ability to precisely target these nanoparticles, offering a potentially successful anticancer treatment for breast cancer. However, additional in vivo assessments of these formulations are obligatory to confirm these findings.

Antitumor activity and targeting p53-PUMA mRNA expression by 5-flurouracil PLGA-lipid polymeric nanoparticles in mouse mammary carcinomas: comparison to free 5-flurouracil

Polymeric poly (lactic-co-glycolic acid) (PLGA)-lipid hybrid nanoparticles (PNPs)-based therapy are powerful carriers for various therapeutic agents. This study was conducted to evaluate the chemotherapeutic potential of free 5-flurouracil (5FU) and synthetized 5FU-PNPs and impact on p53-dependent apoptosis in mammary carcinomas (MCs) grown in mice. Breast cancer cells were injected in Swiss albino female mice and 2 bilateral masses of MC were confirmed after one week. Mice were distributed to five experimental groups; Group 1: MC control group. Groups 2 and 3: MC + free 5FU [5 or 10 mg per kg] groups. Groups 4 and 5: synthetized MC+ 5FU-PNPs [5 or 10 mg per kg] groups. Medications were administered orally, twice weekly for 3 weeks. Then, tumors were dissected, and sections were stained with hematoxylin-eosin (HE) while the other MC was used for measuring of cell death and inflammatory markers. Treatment with 5FU-PNPs suppressed the MC masses and pathologic scores based on HE-staining. Similarly, greater proapoptotic activity was recorded in 5FU-PNPs groups compared to free 5FU groups as shown by significant upregulation in tumoral p53 immunostaining. The current results encourage the utility of PNPs for improving the antitumor effect of 5FU. The chemotherapeutic potential was mediated through enhancement of tumoral p53-mediated p53 up-regulated modulator of apoptosis (PUMA) genes. Additional studies are warranted for testing the antitumor activity of this preparation in other mouse models of breast cancer.

Injectable systems for long-lasting insulin therapy

Insulin therapy is the mainstay to treat diabetes characterizedd by hyperglycemia. However, its short half-life of only 4-6 min limits its effectiveness in treating chronic diabetes. Advances in recombinant DNA technology and protein engineering have led to several insulin analogue products that have up to 42 h of glycemic control. However, these insulin analogues still require once- or twice-daily injections for optimal glycemic control and have poor patient compliance and adherence issues. To achieve insulin release for more than one day, different injectable delivery systems including microspheres, in situ forming depots, nanoparticles and composite systems have been developed. Several of these delivery systems have advanced to clinical trials for once-weekly insulin injection. This review comprehensively summarizes the developments of injectable insulin analogs and delivery systems covering the whole field of injectable long-lasting insulin technologies from prototype design, preclinical studies, clinical trials to marketed products for the treatment of diabetes.

Anti-cancer effect of nano-encapsulated boswellic acids, curcumin and naringenin against HepG-2 cell line

BACKGROUND

liver cancer is one of the most common cancers in the world. So far, there is no gold standard treatment for hepatocellular carcinoma. We conducted this in vitro study to assess the effect of three natural products: Boswellic acids, curcumin and naringin versus corresponding nanoparticles (NPs) on Hep G2 cells proliferation.

METHODS

Boswellic acid, curcumin, naringin-loaded NPs were prepared using nanoprecipitation method. Human liver (HepG2) cell line was cultured in Dulbecco's modified Eagle's medium (DMEM). The cell growth inhibition and cytotoxicity were evaluated by MTT assay.

RESULTS

Boswellic acid, curcumin, naringin were able to inhibit HepG2 cells proliferation. IC50 at 24 h, 48 h showed significant lower values in NPs versus Free herbs. IC50 values of free Boswellic acids and NPs at 24 h were (24.60 ± 1.89 and 7.78 ± 0.54, P < 0.001), at 48 h were (22.45 ± 1.13 and 5.58 ± 0.27, P < 0.001) respectively. IC50 values of free curcumin and NPs at 24 h were (5.89 ± 0.8 and 3.46 ± 0.23, P < 0.05), at 48 h were (5.57 ± 0.94 and 2.51 ± 0.11, P < 0.05), respectively. For free and naringenin NPs, IC50 values at 24 h were (14.57 ± 1.78 and 7.25 ± 0.17, P < 0.01), at 48 h were (11.37 ± 1.45 and 5.21 ± 0.18, P < 0.01) respectively.

CONCLUSION

Boswellic acid, curcumin, naringin and their nanoprecipitation prepared nanoparticles suppressed Hep G2 cells proliferation.

A Perspective on Oral Immunotherapeutic Tools and Strategies for Autoimmune Disorders

Oral immune tolerance is a physiological process to achieve tolerance against autoimmunity by oral ingestion of self-antigen(s) or other therapeutics. At the cellular level, oral tolerance suppresses autoimmune diseases by activating FoxP-positive and -negative regulatory T cells (Tregs) and/or causing clonal anergy or deletion of autoreactive T cells, affecting B cell tolerance. However, oral delivery of antigens/biologics is challenging due to their instability in the harsh environment of the gastrointestinal (GI) tract. Several antigen/drug delivery tools and approaches, including micro/nanoparticles and transgenic plant-based delivery systems, have been explored to demonstrate oral immune tolerance for different autoimmune diseases successfully. However, despite the effectiveness, variation in results, dose optimization, and undesirable immune system activation are the limitations of the oral approach to further advancement. From this perspective, the current review discusses the oral tolerance phenomenon, cellular mechanisms, antigen delivery tools and strategies, and its challenges.

Ligand-switchable nanoparticles resembling viral surface for sequential drug delivery and improved oral insulin therapy

Mutual interference between surface ligands on multifunctional nanoparticles remains a significant obstacle to achieving optimal drug-delivery efficacy. Here, we develop ligand-switchable nanoparticles which resemble viral unique surfaces, enabling them to fully display diverse functions. The nanoparticles are modified with a pH-responsive stretchable cell-penetrating peptide (Pep) and a liver-targeting moiety (Gal) (Pep/Gal-PNPs). Once orally administered, the acidic environments trigger the extension of Pep from surface in a virus-like manner, enabling Pep/Gal-PNPs to traverse intestinal barriers efficiently. Subsequently, Gal is exposed by Pep folding at physiological pH, thereby allowing the specific targeting of Pep/Gal-PNPs to the liver. As a proof-of-concept, insulin-loaded Pep/Gal-PNPs are fabricated which exhibit effective intestinal absorption and excellent hepatic deposition of insulin. Crucially, Pep/Gal-PNPs increase hepatic glycogen production by 7.2-fold, contributing to the maintenance of glucose homeostasis for effective diabetes management. Overall, this study provides a promising approach to achieving full potential of diverse ligands on multifunctional nanoparticles.

Estrone-Conjugated PEGylated Liposome Co-Loaded Paclitaxel and Carboplatin Improve Anti-Tumor Efficacy in Ovarian Cancer and Reduce Acute Toxicity of Chemo-Drugs

Purpose

Ovarian cancer is the most lethal gynecologic malignancy. The combination of paclitaxel (PTX) and carboplatin (CBP) is the first-line remedy for clinical ovarian cancer. However, due to the limitations of adverse reaction and lacking of targeting ability, the chemotherapy of ovarian cancer is still poorly effective. Here, a novel estrone (ES)-conjugated PEGylated liposome co-loaded PTX and CBP (ES-PEG-Lip-PTX/CBP) was designed for overcoming the above disadvantages.

Methods

ES-PEG-Lip-PTX/CBP was prepared by film hydration method and could recognize estrogen receptor (ER) over-expressing on the surface of SKOV-3 cells. The characterizations, stability and in vitro release of ES-PEG-Lip-PTX/CBP were studied. In vitro cellular uptake and its mechanism were observed by fluorescence microscope. In vivo targeting effect in tumor-bearing mice was determined. Pharmacokinetics and biodistribution were studied in ICR mice. In vitro cytotoxicity and in vivo anti-tumor efficacy were evaluated on SKOV-3 cells and tumor-bearing mice, respectively. Finally, the acute toxicity in ICR mice was explored for assessing the preliminary safety of ES-PEG-Lip-PTX/CBP.

Results

Our results showed that ES-PEG-Lip-PTX/CBP was spherical shape without aggregation. ES-PEG-Lip-PTX/CBP exhibited the optimum targeting effect on uptake in vitro and in vivo. The pharmacokinetics demonstrated ES-PEG-Lip-PTX/CBP had improved the pharmacokinetic behavior. In vitro cytotoxicity showed that ES-PEG-Lip-PTX/CBP maximally inhibited SKOV-3 cell proliferation and its IC₅₀ values was 1.6 times lower than that of non-ES conjugated liposomes at 72 h. The in vivo anti-tumor efficacy study demonstrated that ES-PEG-Lip-PTX/CBP could lead strong SKOV-3 tumor growth suppression with a tumor volume inhibitory rate of 81.8%. Meanwhile, acute toxicity studies confirmed that ES-PEG-Lip-PTX/CBP significantly reduced the toxicity of the chemo drugs.

Conclusion

ES-PEG-Lip-PTX/CBP was successfully prepared with an optimal physicochemical and ER targeting property. The data of pharmacokinetics, anti-tumor efficacy and safety study indicated that ES-PEG-Lip-PTX/CBP could become a promising therapeutic formulation for human ovarian cancer in the future clinic.

Rahman N, Wong TW, Chee CF. Challenges and Complications of Poly(lactic-co-glycolic acid)-Based Long-Acting Drug Product Development

Poly(lactic-co-glycolic acid) (PLGA) is one of the preferred polymeric inactive ingredients for long-acting parenteral drug products that are constituted of complex formulations. Despite over 30 years of use, there are still many challenges faced by researchers in formulation-related aspects pertaining to drug loading and release. Until now, PLGA-based complex generic drug products have not been successfully developed. The complexity in developing these generic drug products is not just due to their complex formulation, but also to the manufacturing process of the listed reference drugs that involve PLGA. The composition and product attributes of commercial PLGA formulations vary with the drugs and their intended applications. The lack of standard compendial methods for in vitro release studies hinders generic pharmaceutical companies in their efforts to develop PLGA-based complex generic drug products. In this review, we discuss the challenges faced in developing PLGA-based long-acting injectable/implantable (LAI) drug products; hurdles that are associated with drug loading and release that are dictated by the physicochemical properties of PLGA and product manufacturing processes. Approaches to overcome these challenges and hurdles are highlighted specifically with respect to drug encapsulation and release.

Influence of nanoparticle size on blood-brain barrier penetration and the accumulation of anti-seizure medicines in the brain

Anti-seizure medicines constitute a common yet important modality to treat epilepsy. However, some of them are associated with serious side effects including hepatotoxicity and hypersensitivity. Furthermore, the blood-brain barrier (BBB) is an insurmountable obstacle for brain drug delivery. Fortunately, the introduction of the nanoparticles for drug delivery is a feasible approach to overcome these obstacles. Encapsulating drugs into nanoparticles and delivering them to specific sites shows great potential for improving the efficiency of drug delivery and reducing systemic toxicity. Several in vivo studies have investigated the effect of nanoparticle size on biodistribution in mice, but very few have investigated its effects on efficient drug delivery while crossing the BBB. Therefore, we designed a methoxy poly(lactide-co-glycolide)-b-poly(ethylene glycol) methyl ether (mPEG-PLGA) nanoparticle delivery system and explored the cell uptake efficiency of nanoparticles with different sizes and their ability to penetrate the BBB while carrying carbamazepine (CBZ). CBZ-loaded nanoparticles could significantly reduce the cytotoxicity of CBZ to L929 cells at high concentrations. Results from the endocytosis experiment involving human cerebral microvessel endothelial cell/D3 showed that the DiR-loaded mPEG_5K-PLGA_10K nanoparticles possessed the highest cell uptake efficiency. The endocytosis efficiency was 90% at 30 min, which far exceeded that of the other groups. Moreover, similar results were obtained from subsequent experiments where fluorescence images of the isolated organs of the mice were acquired. To summarize, our study demonstrated that drug delivery to the brain using nanocarriers is size dependent. Nanoparticles with the smallest particle size can be internalized more effectively, and easily penetrate the BBB, and accumulate in the brain.

In Vitro Comparative Study of Solid Lipid and PLGA Nanoparticles Designed to Facilitate Nose-to-Brain Delivery of Insulin

The brain insulin metabolism alteration has been addressed as a pathophysiological factor underlying Alzheimer's disease (AD). Insulin can be beneficial in AD, but its macro-polypeptide nature negatively influences the chances of reaching the brain. The intranasal (IN) administration of therapeutics in AD suggests improved brain-targeting. Solid lipid nanoparticles (SLNs) and poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) are promising carriers to deliver the IN-administered insulin to the brain due to the enhancement of the drug permeability, which can even be improved by chitosan-coating. In the present study, uncoated and chitosan-coated insulin-loaded SLNs and PLGA NPs were formulated and characterized. The obtained NPs showed desirable physicochemical properties supporting IN applicability. The in vitro investigations revealed increased mucoadhesion, nasal diffusion, and drug release rate of both insulin-loaded nanocarriers over native insulin with the superiority of chitosan-coated SLNs. Cell-line studies on human nasal epithelial and brain endothelial cells proved the safety IN applicability of nanoparticles. Insulin-loaded nanoparticles showed improved insulin permeability through the nasal mucosa, which was promoted by chitosan-coating. However, native insulin exceeded the blood-brain barrier (BBB) permeation compared with nanoparticulate formulations. Encapsulating insulin into chitosan-coated NPs can be beneficial for ensuring structural stability, enhancing nasal absorption, followed by sustained drug release.

Development and Evaluation of Icariin-Loaded PLGA-PEG Nanoparticles for Potentiation the Proapoptotic Activity in Pancreatic Cancer Cells

Therapeutic efficacy of antineoplastic agents possessing a selective target to the nucleus of the cancer cells could be enhanced through novel formulation approaches. Thus, towards improvement of anticancer potential of icariin (ICA) on pancreatic cancer, the drug was entrapped into the polymeric poly lactic-co-glycolic acid (PLGA) with polyethylene glycol (PEG) as diblock copolymer. Optimization of the formulation was done using Statgraphics software to standardize percentages of PEG-PLGA and tween 80 (TW80) to obtain the smallest particle size. The optimized formulation was found to be in nanometer size and low PDI (0.321). Optimized formula enhanced cytotoxicity and apoptotic potential, compared with ICA-raw, against pancreatic cancer cell lines (aspc-1). The entrapment efficiency of the polymeric micelles was 72.34 ± 2.3% with 93.1 ± 6.5% release of ICA within 72 h. There was a twofold increase in apoptosis and sevenfold increase in necrosis of aspc-1 cells when incubated with raw ICA compared to control cells. Further, loss of mitochondrial membrane potential (⁓50-fold) by the ICA-loaded PMs and free drug compared to control cells was found to be due to the generation of ROS. Findings of cell cycle analysis revealed the significant arrest of G2-M phase of aspc-1 cells when incubated with the optimized formulation. Simultaneously, a significantly increased number of cells in pre-G1 revealed maximum apoptotic potential of the drug when delivered via micellar formulation. Finally, upregulation of caspase-3 established the superiority of the PMs approach against pancreatic cancer. In summary, the acquired results highlighted the potentiality of PMs delivery tool for controlling the growth of pancreatic cancer cells for improved efficacy.

Particle engineering principles and technologies for pharmaceutical biologics

The global market of pharmaceutical biologics has expanded significantly during the last few decades. Currently, pharmaceutical biologic products constitute an indispensable part of the modern medicines. Most pharmaceutical biologic products are injections either in the forms of solutions or lyophilized powders because of their low oral bioavailability. There are certain pharmaceutical biologic entities formulated into particulate delivery systems for the administration via non-invasive routes or to achieve prolonged pharmaceutical actions to reduce the frequency of injections. It has been well documented that the design of nano- and microparticles via various particle engineering technologies could render pharmaceutical biologics with certain benefits including improved stability, enhanced intracellular uptake, prolonged pharmacological effect, enhanced bioavailability, reduced side effects, and improved patient compliance. Herein, we review the principles of the particle engineering technologies based on bottom-up approach and present the important formulation and process parameters that influence the critical quality attributes with some mathematical models. Subsequently, various nano- and microparticle engineering technologies used to formulate or process pharmaceutical biologic entities are reviewed. Lastly, an array of commercialized products of pharmaceutical biologics accomplished based on various particle engineering technologies are presented and the challenges in the development of particulate delivery systems for pharmaceutical biologics are discussed.

Development and Optimization of Luliconazole Spanlastics to Augment the Antifungal Activity against Candida albicans

Luliconazole is a new topical imidazole antifungal drug for the treatment of skin infections. It has low solubility and poor skin penetration which limits its therapeutic applications. In order to improve its therapeutic efficacy, spanlastics nanoformulation was developed and optimized using a combined mixture-process variable design (CMPV). The optimized formulation was converted into a hydrogel formula to enhance skin penetration and increase the efficacy in experimental cutaneous Candida albicans infections in Swiss mice wounds. The optimized formulation was generated at percentages of Span and Tween of 48% and 52%, respectively, and a sonication time of 6.6 min. The software predicted that the proposed formulation would achieve a particle size of 50 nm with a desirability of 0.997. The entrapment of luliconazole within the spanlastics carrier showed significant (p < 0.0001) antifungal efficacy in the immunocompromised Candida-infected Swiss mice without causing any irritation, when compared to the luliconazole treated groups. The microscopic observation showed almost complete removal of the fungal colonies on the skin of the infected animals (0.2 ± 0.05 log CFU), whereas the control animals had 0.2 ± 0.05 log CFU. Therefore, luliconazole spanlastics could be an effective formulation with improved topical delivery for antifungal activity against C. albicans.

An overview of PLGA in-situ forming implants based on solvent exchange technique: effect of formulation components and characterization

As a result of the low oral bioavailability of several drugs, there is a renewed interest for parenteral administration to target their absorption directly into the blood bypassing the long gastrointestinal route and hepatic metabolism. In order to address the potential side effects of frequent injections, sustained release systems are the most popular approaches for achieving controlled long-acting drug delivery. Injectable in-situ forming implants (ISFIs) have gained greater popularity in comparison to other sustained systems. Their significant positive aspects are attributed to easier production, acceptable administration route, reduced dosing frequency and patient compliance achievement. ISFI systems, comprising biodegradable polymers such as poly (lactide-co-glycolide) (PLGA) based on solvent exchange mechanisms, are emerged as liquid formulations that develop solid or semisolid depots after injection and deliver drugs over extended periods. The drug release from ISFI systems is generally characterized by an initial burst during the matrix solidification, followed by diffusion processes and finally polymeric degradation and erosion. The choice of suitable solvent with satisfactory viscosity, miscibility and biocompatibility along with considerable PLGA hydrophobicity and molecular weights is fundamental for optimizing the drug release. This overview gives a particular emphasis on evaluations and the wide ranges of requirements needed to achieve reasonable physicochemical characteristics of ISFIs.

Formulation and In Vitro Characterization of PLGA/PLGA-PEG Nanoparticles Loaded with Murine Granulocyte-Macrophage Colony-Stimulating Factor

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has demonstrated notable clinical activity in cancer immunotherapy, but it is limited by systemic toxicities, poor bioavailability, rapid clearance, and instability in vivo. Nanoparticles (NPs) may overcome these limitations and provide a mechanism for passive targeting of tumors. This study aimed to develop GM-CSF-loaded PLGA/PLGA-PEG NPs and evaluate them in vitro as a potential candidate for in vivo administration. NPs were created by a phase-separation technique that did not require toxic/protein-denaturing solvents or harsh agitation techniques and encapsulated GM-CSF in a more stable precipitated form. NP sizes were within 200 nm for enhanced permeability and retention (EPR) effect with negative zeta potentials, spherical morphology, and high entrapment efficiencies. The optimal formulation was identified by sustained release of approximately 70% of loaded GM-CSF over 24 h, alongside an average size of 143 ± 35 nm and entrapment efficiency of 84 ± 5%. These NPs were successfully freeze-dried in 5% (w/v) hydroxypropyl-β-cyclodextrin for long-term storage and further characterized. Bioactivity of released GM-CSF was determined by observing GM-CSF receptor activation on murine monocytes and remained fully intact. NPs were not cytotoxic to murine bone marrow-derived macrophages (BMDMs) at concentrations up to 1 mg/mL as determined by MTT and trypan blue exclusion assays. Lastly, NP components generated no significant transcription of inflammation-regulating genes from BMDMs compared to IFNγ+LPS "M1" controls. This report lays the preliminary groundwork to validate in vivo studies with GM-CSF-loaded PLGA/PEG-PLGA NPs for tumor immunomodulation. Overall, these data suggest that in vivo delivery will be well tolerated.

Overview of key molecular and pharmacological targets for diabetes and associated diseases

Diabetes epidemiological quantities are demonstrating one of the most important communities' health worries. The essential diabetic difficulties are including cardiomyopathy, nephropathy, inflammation, and retinopathy. Despite developments in glucose decreasing treatments and drugs, these diabetic complications are still ineffectively reversed or prohibited. Several signaling and molecular pathways are vital targets in the new therapies of diabetes. This review assesses the newest researches about the key molecules and signaling pathways as targets of molecular pharmacology in diabetes and diseases related to it for better treatment based on molecular sciences. The disease is not cured by current pharmacological strategies for type 2 diabetes. While several drug combinations are accessible that can efficiently modulate glycemia and mitigate long-term complications, these agents do not reverse pathogenesis, and in practice, they are not established to modify the patient's specific molecular profiling. Therapeutic companies have benefited from human genetics. Genome exploration, which is agnostic to the information that exists, has revealed tens of loci that impact glycemic modulation. The physiological report has begun to examine subtypes of diseases, illustrate heterogeneity and propose biochemical therapeutic pathways.

Formulation of stabilizer-free, nontoxic PLGA and elastin-PLGA nanoparticle delivery systems

Biocompatible nanoparticles composed of poly(lactic-co-glycolic acid) (PLGA) are used as drug and vaccine delivery systems because of their tunability in size and sustained release of cargo molecules. While the use of toxic stabilizers such as polyvinyl alcohol (PVA) limit the utility of PLGA, stabilizer-free PLGA nanoparticles are rarely used because they can be challenging to prepare. Here, we developed a tunable, stabilizer-free PLGA nanoparticle formulation capable of encapsulating plasmid DNA and demonstrated the formation of an elastin-like polymer PLGA hybrid nanoparticle with exceptional stability and biocompatibility. A suite of PLGAs were fabricated using solvent evaporation methods and assessed for particle size and stability in water. We find that under physiological conditions (PBS at 37˚C), the most stable PLGA formulation (P4) was found to contain a greater L:G ratio (65:35), lower MW, and carboxyl terminus. Subsequent experiments determined P4 nanoparticles were as stable as those made with PVA, yet significantly less cytotoxic. Variation in particle size was achieved through altering PLGA stoichiometry while maintaining the ability to encapsulate DNA and were modified with elastin-like polymers for increased immune tolerance. Overall, a useful method for tunable, stabilizer-free PLGA nanoparticle formulation was developed for use in drug and vaccine delivery, and immune targeting.

Poly ethylene glycol (PEG)-Related controllable and sustainable antidiabetic drug delivery systems

Diabetes mellitus is one of the most challenging threats to global public health. To improve the therapy efficacy of antidiabetic drugs, numerous drug delivery systems have been developed. Polyethylene glycol (PEG) is a polymeric family sharing the same skeleton but with different molecular weights which is considered as a promising material for drug delivery. In the delivery of antidiabetic drugs, PEG captures much attention in the designing and preparation of sustainable and controllable release systems due to its unique features including hydrophilicity, biocompatibility and biodegradability. Due to the unique architecture, PEG molecules are also able to shelter delivery systems to decrease their immunogenicity and avoid undesirable enzymolysis. PEG has been applied in plenty of delivery systems such as micelles, vesicles, nanoparticles and hydrogels. In this review, we summarized several commonly used PEG-contained antidiabetic drug delivery systems and emphasized the advantages of stimuli-responsive function in these sustainable and controllable formations.

pH-Responsive Cellulose-Based Microspheres Designed as an Effective Oral Delivery System for Insulin

Functional modified cellulose microsphere (CMs) materials exhibit great application potential in drug various fields. Here, we designed pH-responsive carboxylated cellulose microspheres (CCMs) by the citric/hydrochloric acid hydrolysis method to enhance oral bioavailability of insulin by a green route. The CMs were high purity cellulose that dissolved and regenerated from a green solvent by the green sol-gel method. The prepared microspheres were characterized by spectroscopic techniques, such as field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrum (FT-IR), X-ray diffraction (XPS), etc. The spherical porous structure and carboxylation of cellulose were confirmed by FESEM and FT-IR, respectively. Insulin was loaded into the CCMs by electrostatic interactions, and the insulin release was controlled through ionization of carboxyl groups and proton balance. In vitro insulin release profiles demonstrated the suppression of insulin release in artificial gastric fluid (AGF), while a significant increase at artificial intestinal fluid (AIF) was observed. The insulin release profile was fitted in Korsmeyer-Peppas kinetic model, and insulin release was governed by the Fickian diffusion mechanism. The stability of the secondary structure of insulin was studied by dichroism circular. Excellent biocompatibility and no cytotoxicity of designed CCMs cast them as a potential oral insulin carrier.

Polymeric nanoencapsulation of zaleplon into PLGA nanoparticles for enhanced pharmacokinetics and pharmacological activity

Zaleplon (ZP) is a sedative and hypnotic drug used for the treatment of insomnia. Despite its potent anticonvulsant activity, ZP is not commonly used for the treatment of convulsion since ZP is characterized by its low oral bioavailability as a result of poor solubility and extensive liver metabolism. The following study aimed to formulate specifically controlled release nano-vehicles for oral and parenteral delivery of ZP to enhance its oral bioavailability and biological activity. A modified single emulsification-solvent evaporation method of sonication force was adopted to optimize the inclusion of ZP into biodegradable nanoparticles (NPs) using poly (dl-lactic-co-glycolic acid) (PLGA). The impacts of various formulation variables on the physicochemical characteristics of the ZP-PLGA-NPs and drug release profiles were investigated. Pharmacokinetics and pharmacological activity of ZP-PLGA-NPs were studied using experimental animals and were compared with generic ZP tablets. Assessment of gamma-aminobutyric acid (GABA) level in plasma after oral administration was conducted using enzyme-linked immunosorbent assay. The maximal electroshock-induced seizures model evaluated anticonvulsant activity after the parenteral administration of ZP-loaded NPs. The prepared ZP-PLGA NPs were negatively charged spherical particles with an average size of 120-300 nm. Optimized ZP-PLGA NPs showed higher plasma GABA levels, longer sedative, hypnotic effects, and a 3.42-fold augmentation in oral drug bioavailability in comparison to ZP-marketed products. Moreover, parenteral administration of ZP-NPs showed higher anticonvulsant activity compared to free drug. Oral administration of ZP-PLGA NPs achieved a significant improvement in the drug bioavailability, and parenteral administration showed a pronounced anticonvulsant activity.

Development of Rifapentine-Loaded PLGA-Based Nanoparticles: In vitro Characterisation and in vivo Study in Mice

Background

Tuberculosis (TB) is a leading cause of death amongst infectious diseases. The poor response to antitubercular agents necessitates the long-term use of high drug doses, resulting in low patient compliance, which is the main reason for chemotherapy failure and contributes to the development of multidrug-resistant TB. Patient non-compliance has been a major obstacle in the successful management of TB. The aim of this work was to develop and characterise rifapentine (RPT)-loaded PLGA-based nanoparticles (NPs) for reducing dosing frequency.

Methods

RPT-loaded PLGA and PLGA–PEG NPs were prepared using premix membrane homogenisation combined with solvent evaporation method. The resulting NPs were characterised in terms of physicochemical characteristics, toxicity, cellular uptake and antitubercular activity. NPs were further evaluated for pharmacokinetic and biodistribution studies in mice.

Results

The resulting NPs showed suitable and safe physicochemical characteristics and could be taken up by macrophages. RPT-loaded NPs were more effective against Mycobacterium tuberculosis than free RPT. In vivo studies revealed that NPs could improve pharmacokinetic parameters, particularly for RPT/PLGA–PEG NPs. Moreover, both formulations had no toxicity to the organs of mice and could reduce hepatotoxicity.

Conclusion

The application of PLGA-based NPs as sustained-release delivery vehicles for RPT could prolong drug release, modify pharmacokinetics, increase antitubercular activity and diminish toxicity, thereby allowing low dosage and frequency.

Biodegradable self-assembled nanoparticles of PEG-PLGA amphiphilic diblock copolymer as a promising stealth system for augmented vinpocetine brain delivery

Vinpocetine (VNP), a semisynthetic drug, is utilized for the treatment of cerebrovascular and memory disorders. This work aimed at formulation of biodegradable VNP long-circulating nanoparticles utilizing Polyethylene glycol methyl ether-block-poly lactide-co-glycolide (PEG-PLGA) copolymer to surmount the drug drawbacks including low oral bioavailability and short elimination half-life. VNP nanoparticles were formulated using nanoprecipitation technique. A 2⁴ factorial design was applied to assess the impact of formulation and process variables on the nanoparticles' characteristics. Statistical analysis revealed that nanoparticles size (Y₁) significantly increased with increasing PEG-PLGA amount (X₁), poly-vinyl alcohol concentration (X₂), and PLGA content (X₄), while decreased with increasing sonication time (X₃). Furthermore, the entrapment efficiency (Y₂) was positively affected by both PEG-PLGA amount and PLGA content, while negatively affected by poly-vinyl alcohol concentration. The optimized formulation prepared using 200 mg of PEG-PLGA polymer (PEG: PLGA 2000: 4,500), 0.5% polyvinyl alcohol with sonication time of 60 s achieved spherical shape with particle size of 43 nm and drug entrapment of 82%. A significant bioavailability enhancement of VNP with marked prolongation of the in vivo systemic exposure of the drug and increased brain levels has also been achieved following intraperitoneal administration in Wistar rats. Thus, the optimized formulation could be regarded as a promising stealth nanocarrier that could surmount the drug pitfalls and enhance its brain delivery.

Formulation and Optimization of Avanafil Biodegradable Polymeric Nanoparticles: A Single-Dose Clinical Pharmacokinetic Evaluation

Avanafil (AVA) is a second-generation phosphodiesterase-5 (PDE5) inhibitor. AVA shows high selectivity to penile tissues and fast absorption, but has a bioavailability of about 36%. The aim was to formulate and optimize AVA-biodegradable nanoparticles (NPs) to enhance AVA bioavailability. To assess the impact of variables, the Box–Behnken design was utilized to investigate and optimize the formulation process variables: the AVA:poly (lactic-co-glycolic acid) (PLGA) ratio (w/w, X1); sonication time (min, X2); and polyvinyl alcohol (PVA) concentration (%, X3). Particle size (nm, Y1) and EE% (%, Y2) were the responses. The optimized NPs were characterized for surface morphology and permeation. Furthermore, a single-oral dose (50 mg AVA) pharmacokinetic investigation on healthy volunteers was carried out. Statistical analysis revealed that all the investigated factors exhibited a significant effect on the particle size. Furthermore, the entrapment efficiency (Y2) was significantly affected by both the AVA:PLGA ratio (X1) and PVA concentration (X3). Pharmacokinetic data showed a significant increase in the area under the curve (1.68 folds) and plasma maximum concentration (1.3-fold) for the AVA NPs when compared with raw AVA. The optimization and formulation of AVA as biodegradable NPs prepared using solvent evaporation (SE) proves a successful way to enhance AVA bioavailability.

Multiple targeting strategies achieve novel protein drug delivery into proapoptosis lung cancer cells by precisely inhibiting survivin

Therapeutic recombinant proteins have numerous advantages and benefits over chemical drugs, particularly high specificity and good biocompatibility. However, the therapeutic potential and clinical application of current anticancer protein drugs are limited as most biomarkers are located within cells, and multiple physiological barriers exist between the point of administration and the intracellular biomarker. Herein, we report a novel strategy to accurately deliver a cell-permeable dominant-negative TATm-Survivin (TmSm) protein (T34A) to intracellular survivin in cancer cells by overcoming multiple barriers in vivo. A poly(d,l-lactide-co-glycolide) (PLGA) inner core, a polyethylene glycol (PEG) modification, and a TATm peptide were simultaneously introduced to mediate tumor tissue targeting and response to pH-triggered TmSm release. Compared to free TmSm, the PEGylated-PLGA nanoparticle platform achieved a significantly higher cellular uptake efficiency (1.79-fold for A549 and 1.77-fold for Capan-2), effectively decreased IC50 (1.22-fold for A549 and 1.17-fold for Capan-2), and largely elevated apoptosis in different cancer cells (1.17-fold for A549 and 1.15-fold for Capan-2). Besides, this newly developed nanoplatform showed increased protein drug accumulation in the tumor site in A549-bearing nude mice and reached a tumor inhibition rate of 55.81% (1.35-fold versus free TmSm) by reducing the expression of intracellular survivin. All these results confirmed that our newly developed delivery strategy is a very promising tool, which helps protein drugs to cross multiple barriers in vivo and achieves precise targeting to intracellular biomarkers. This strategy could also be applied to other types of protein drugs to further improve their clinical anticancer therapeutic efficacy.

Nanoencapsulation of sophorolipids in PEGylated poly(lactide-co-glycolide) as a novel approach to target colon carcinoma in the murine model

Poly(lactic-co-glycolic acid) nanocapsules containing amphiphilic biosurfactant sophorolipids were formulated using a dispersion-based procedure. Di-block copolymers were used to vary peripheral poly(ethylene glycol) density, and variation in the oil core was used to achieve efficient encapsulation of the sophorolipid payload. Particulate size, zeta potential, encapsulation efficiency, release and stability were characterised. A glyceryl monocaprate core composition had the lowest particulate size, maximum encapsulation efficiency and optimum shelf-life stability compared to other formulations. This core composition was used to deliver sophorolipid to both in vitro and in vivo model tumour cell lines (CT26 murine colon carcinoma) and the effect of peripheral hydrophilicity was evaluated. Formulations with 10% poly(ethylene glycol) density achieved more than 80% reduction in cancer cell viability after 72 h and enhanced cellular uptake in CT26 cells. These formulations exhibited higher tumour accumulation and a longer blood circulation profile when compared to the non-poly(ethylene glycol)-containing nanocapsules. Animals treated with sophorolipid-loaded nanocapsules showed a tumour growth inhibition of 57% when compared to controls. An assessment of tumour mass within the same study cohort showed the biggest reduction when compared control and free drug-treated cohorts. This study shows that hydrophilic poly(lactic-co-glycolic acid) nanocapsules loaded with sophorolipids can address the poor intracellular delivery associated with these biosurfactants and is a promising approach for the treatment of colon neoplasia.

Design, Formulation and in vivo Evaluation of Novel Honokiol-Loaded PEGylated PLGA Nanocapsules for Treatment of Breast Cancer

Background

Honokiol (HK) is a common herbal medicine extracted from magnolia plants. Low aqueous solubility and limited bioavailability of HK have hindered its clinical application, especially for cancer treatment. Nano-drug delivery system has the potential to enhance HK delivery and therefore, enhance its anti-cancer activity.

Purpose

The study’s aim is to design novel PEGylated-PLGA polymeric nanocapsules (NCs) for HK delivery to breast tumor-bearing mice after systemic administration.

Methods

Formulation of different HK-loaded NCs and their physio-chemical characterization were optimized through the use of different formulation variables. The antitumor activity of the HK-loaded NCs was investigated both in vitro using MCF-7 and EAC breast cancer cell lines and in vivo using solid Ehrlich carcinoma (SEC) breast cancer model.

Results

The optimum HK-loaded NCs were prepared from 15% PEG-PLGA diblock copolymer and exhibited the lowest nano size of 125 nm, smooth spherical morphology, highest drug loading of 94% and highest cellular uptake into breast cancer cells. HK-loaded PEGylated NCs can effectively inhibit the in vitro cell growth of breast cancer cells by 80.2% and 58.1% compared to 35% and 31% with free HK in the case of MCF-7 and EAC, respectively. HK-loaded NCs inhibited SEC tumor growth by 2.3 fold significantly higher than free HK, in vivo.

Conclusion

The designed drug delivery system encapsulating HK exhibited a pronounced decrease in tumor growth biomarkers meanwhile proved its safety in animals. Therefore, 15% PEGylated HK-loaded NCs may act as a promising new approach for breast cancer treatment.

Recent Avenues in Novel Patient-Friendly Techniques for the Treatment of Diabetes

Background:

Diabetes is one of the most common chronic metabolic disorders which affect the quality of human life worldwide. As per the WHO report, between 1980 to 2014, the number of diabetes patients increases from 108 million to 422 million, with a global prevalence rate of 8.5% per year. Diabetes is the prime reason behind various other diseases like kidney failure, stroke, heart disorders, glaucoma, etc. It is recognized as the seventh leading cause of death throughout the world. The available therapies are painful (insulin injections) and inconvenient due to higher dosing frequency. Thus, to find out a promising and convenient treatment, extensive investigations are carried out globally by combining novel carrier system (like microparticle, microneedle, nanocarrier, microbeads etc.) and delivery devices (insulin pump, stimuli-responsive device, inhalation system, bioadhesive patch, insulin pen etc.) for more precise diagnosis and painless or less invasive treatment of disease.

Objective:

The review article is made with an objective to compile information about various upcoming and existing modern technologies developed to provide greater patient compliance and reduce the undesirable side effect of the drug. These devices evade the necessity of daily insulin injection and offer a rapid onset of action, which sustained for a prolonged duration of time to achieve a better therapeutic effect.

Conclusion:

Despite numerous advantages, various commercialized approaches, like Afrezza (inhalation insulin) have been a failure in recent years. Such results call for more potential work to develop a promising system. The novel approaches range from the delivery of non-insulin blood glucose lowering agents to insulin-based therapy with minimal invasion are highly desirable.

Albumin Nano-Encapsulation of Piceatannol Enhances Its Anticancer Potential in Colon Cancer Via Downregulation of Nuclear p65 and HIF-1α

Piceatannol (PIC) is known to have anticancer activity, which has been attributed to its ability to block the proliferation of cancer cells via suppression of the NF-kB signaling pathway. However, its effect on hypoxia-inducible factor (HIF) is not well known in cancer. In this study, PIC was loaded into bovine serum albumin (BSA) by desolvation method as PIC–BSA nanoparticles (NPs). These PIC–BSA nanoparticles were assessed for in vitro cytotoxicity, migration, invasion, and colony formation studies and levels of p65 and HIF-1α. Our results indicate that PIC–BSA NPs were more effective in downregulating the expression of nuclear p65 and HIF-1α in colon cancer cells as compared to free PIC. We also observed a significant reduction in inflammation induced by chemical colitis in mice by PIC–BSA NPs. Furthermore, a significant reduction in tumor size and number of colon tumors was also observed in the murine model of colitis-associated colorectal cancer, when treated with PIC–BSA NPs as compared to free PIC. The overall results indicate that PIC, when formulated as PIC–BSA NPs, enhances its therapeutic potential. Our work could prompt further research in using natural anticancer agents as nanoparticels with possible human clinical trails. This could lead to the development of a new line of safe and effective therapeutics for cancer patients.

Low molecular weight PEG-PLGA polymers provide a superior matrix for conjugated polymer nanoparticles in terms of physicochemical properties, biocompatibility and optical/photoacoustic performance

The near-infrared absorbing conjugated polymer poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) has been investigated as a contrast agent for optical and photoacoustic imaging. Lipophilic π-conjugated polymers can be efficiently encapsulated within self-assembling diblock copolymer poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG-PLGA) nanoparticles, although the effect of variations in PEG and PLGA chain lengths on nanoparticle properties, performance and biocompatibility have not yet been investigated. In this study, PEG-PLGA with different block lengths (PEG_2kDa-PLGA_4kDa, PEG_2kDa-PLGA_15kDa and PEG_5kDa-PLGA_55kDa) were used to encapsulate PCPDTBT. Nanoparticle sizes were smallest (<100 nm) when using PEG_2kDa-PLGA_4kDa, with <5% PCPDTBT content and a reduction in the total solids concentration of the organic phase. All PEG-PLGA nanoparticles were colloidally stable in water and serum-supplemented cell culture medium over 24 h at 37 °C, with slight evidence of protein surface adsorption. PEG_2kDa-PLGA_4kDa systems showed a threefold lower cytotoxicity (IC₅₀ value) than the other two systems. Haemolytic activity was <2.5% for all systems and no platelet aggregation or inhibition of ADP-induced platelet aggregation was observed. Encapsulation of PCPDTBT within a PEG-PLGA matrix shifted fluorescence emission towards red wavelengths (760 nm in THF vs. 840 nm in nanoparticles) and reduced the quantum yield by 30-70-fold compared to THF. Nonetheless, PCPDTBT:PEG_2kDa-PLGA_4kDa systems had a marginally higher quantum yield and signal-to-background ratio in a phantom mouse compared with PEG_2kDa-PLGA_15kDa and PEG_5kDa-PLGA_55kDa systems. As a photoacoustic imaging probe, PCPDTBT:PEG_2kDa-PLGA_4kDa systems also showed a higher photoacoustic amplitude compared to higher molecular weight PEG-PLGA systems. Overall, the low molecular weight PEG_2kDa-PLGA_4kDa nanoparticle systems conferred the benefits of smaller sizes, reduced cytotoxicity and enhanced imaging performance compared to higher molecular weight matrix polymers.

Synthesis and Statistical Optimization of Poly (Lactic-Co-Glycolic Acid) Nanoparticles Encapsulating GLP1 Analog Designed for Oral Delivery

Purpose

To design and stabilize Liraglutide loaded poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) proper for oral administration.

Methods

PLGA NPs were prepared by means of double emulsion solvent evaporation method and optimized by applying 7-factor 2-level Plackett-Burman screening design.

Results

Spherical shaped NPs with homogeneous distribution, 188.95 nm particle size and 51.81% encapsulation efficiency were obtained. Liraglutide was successfully entrapped in the NPs while maintaining its native amorphous nature, and its structural integrity as well.

Conclusion

Lira-PLGA NPs with the required Critical Quality Attributes (CQAs) were successfully designed by implementing a 7-factor 8-run Plackett Burman design into the extended Quality by Design (QbD) model, to elucidate the effect of formulation and process variables on the particle size, size-distribution, encapsulation efficiency and surface charge. As the developed nanoparticles maintained the native structure of the active pharmaceutical ingredient (API), they are promising compositions for the further development for the oral delivery of Lira.

Engineering of L-Plastin Peptide-Loaded Biodegradable Nanoparticles for Sustained Delivery and Suppression of Osteoclast Function In Vitro

We have recently demonstrated that a small molecular weight amino-terminal peptide of L-plastin (10 amino acids; “MARGSVSDEE”) suppressed the phosphorylation of endogenous L-plastin. Therefore, the formation of nascent sealing zones (NSZs) and bone resorption are reduced. The aim of this study was to develop a biodegradable and biocompatible PLGA nanocarrier that could be loaded with the L-plastin peptide of interest and determine the efficacy in vitro in osteoclast cultures. L-plastin MARGSVSDEE (P1) and scrambled control (P3) peptide-loaded PLGA-PEG nanoparticles (NP1 and NP3, respectively) were synthesized by double emulsion technique. The biological effect of nanoparticles on osteoclasts was evaluated by immunoprecipitation, immunoblotting, rhodamine-phalloidin staining of actin filaments, and pit forming assays. Physical characterization of well-dispersed NP1 and NP3 demonstrated ~130-150 nm size, < 0.07 polydispersity index, ~-3 mV ζ-potential, and a sustained release of the peptide for three weeks. Biological characterization in osteoclast cultures demonstrated the following: NP1 significantly reduced (a) endogenous L-plastin phosphorylation; (b) formation of NSZs and sealing rings; (c) resorption. However, the assembly of podosomes which are critical for cell adhesion was not affected. L-plastin peptide-loaded PLGA-PEG nanocarriers have promising potential for the treatment of diseases associated with bone loss. Future studies will use this sustained release of peptide strategy to systematically suppress osteoclast bone resorption activity in vivo in mouse models demonstrating bone loss.

Novel Ran-RCC1 Inhibitory Peptide-Loaded Nanoparticles Have Anti-Cancer Efficacy In Vitro and In Vivo

The delivery of anticancer agents to their subcellular sites of action is a significant challenge for effective cancer therapy. Peptides, which are integral to several oncogenic pathways, have significant potential to be utilised as cancer therapeutics due to their selectivity, high potency and lack of normal cell toxicity. Novel Ras protein-Regulator of chromosome condensation 1 (Ran-RCC1) inhibitory peptides designed to interact with Ran, a novel therapeutic target in breast cancer, were delivered by entrapment into polyethylene glycol-poly (lactic-co-glycolic acid) PEG-PLGA polymeric nanoparticles (NPs). A modified double emulsion solvent evaporation technique was used to optimise the physicochemical properties of these peptide-loaded biodegradable NPs. The anti-cancer activity of peptide-loaded NPs was studied in vitro using Ran-expressing metastatic breast (MDA-MB-231) and lung cancer (A549) cell lines, and in vivo using Solid Ehrlich Carcinoma-bearing mice. The anti-metastatic activity of peptide-loaded NPs was investigated using migration, invasion and colony formation assays in vitro. A PEG-PLGA-nanoparticle encapsulating N-terminal peptide showed a pronounced antitumor and anti-metastatic action in lung and breast cancer cells in vitro and caused a significant reduction of tumor volume and associated tumor growth inhibition of breast cancer model in vivo. These findings suggest that the novel inhibitory peptides encapsulated into PEGylated PLGA NPs are delivered effectively to interact and deactivate Ran. This novel Ran-targeting peptide construct shows significant potential for therapy of breast cancer and other cancers mediated by Ran overexpression.

Molecular Self-Assembly Strategy for Encapsulation of an Amphipathic α-Helical Antimicrobial Peptide into the Different Polymeric and Copolymeric Nanoparticles

Encapsulation of peptide and protein-based drugs in polymeric nanoparticles is one of the fundamental fields in controlled-release drug delivery systems. The molecular mechanisms of absorption of peptides to the polymeric nanoparticles are still unknown, and there is no precise molecular data on the encapsulation process of peptide and protein-based drugs. Herein, the self-assembly of different polymers and block copolymers with combinations of the various molecular weight of blocks and the effects of resultant polymer and copolymer nanomicelles on the stability of magainin2, an α-helical antimicrobial peptide, were investigated by means of all-atom molecular dynamics (MD) simulation. The micelle forming, morphology of micellar aggregations and changes in the first hydration shell of the micelles during micelles formation were explored as well. The results showed that the peptide binds to the polymer and copolymer micelles and never detaches during the MD simulation time. In general, all polymers and copolymers simultaneously encapsulated the peptide during micelles formation and had the ability to maintain the helical structure of the peptide, whereas the first hydration shell of the peptide remained unchanged. Among the micelles, the polyethylene glycol (PEG) micelles completely encapsulated magainin2 and, surprisingly, the NMR structure of the peptide was perfectly kept during the encapsulation process. The MD results also indicated that the aromatic and basic residues of the peptide strongly interact with polymers/copolymers and play important roles in the encapsulation mechanism. This research will provide a good opportunity in the design of polymer surfaces for drug delivery applications such as controlled-release peptide delivery systems.

Design of ciprofloxacin-loaded nano-and microcomposite particles for dry powder inhaler formulations: preparation, in vitro characterisation, and antimicrobial efficacy

In this study, ciprofloxacin hydrochloride (CIP)-loaded poly-ε-caprolactone (PCL) nanoparticles were prepared for pulmonary administration. CIP-loaded PCL nanoparticles were prepared using solid-in-oil-in-water (s/o/w) emulsion solvent evaporation method, and the effects of various formulation parameters on the physicochemical properties of the nanoparticles were investigated. PCL nanoparticles showed spherical shapes with particle sizes around 143-489 nm. Encapsulation efficiency was found to be very low because of water-solubility properties of CIP. However, the surface modification of nanoparticles with chitosan caused an increase in the encapsulation efficiency of nanoparticles. At drug release study, CIP-loaded PCL nanoparticles showed initial burst effect for 4 h and then continuously released for 72 h. Nanocomposite microparticles containing CIP-loaded PCL nanoparticles were prepared freeze-drying method and mannitol was used as carrier material. Tapped density and MMADt results show that nanocomposite microparticles have suitable aerodynamic properties for pulmonary administration. Antimicrobial efficacy investigations showed that CIP-encapsulated PCL nanoparticles and nanocomposite microparticles inhibited the growth of bacteria. Also, when the antimicrobial activity of the nanoparticles at the beginning and at the sixth month was examined, it was found that the structure of the particulate system was still preserved. These results indicated that nanocomposite microparticles containing CIP-loaded PCL nanoparticles can be used for pulmonary delivery.

Reassessment of long circulation via monitoring of integral polymeric nanoparticles justifies a more accurate understanding

Monitoring of payloads results in a biased perception of long circulation of nanoparticles. Instead, herein, the long-circulation effect was re-confirmed by monitoring integral nanoparticles, but circulation was not found to be as long as generally perceived. In contrast, disparate pharmacokinetics were obtained by monitoring a model drug, paclitaxel, highlighting the bias of the conventional protocol.

Antigen-Specific Tolerization and Targeted Delivery as Therapeutic Strategies for Autoimmune Diseases

The prevalence of autoimmune disorders is increasing steadily and there is no permanent cure available. Immunomodulation through repeated exposure of antigens, known as antigen-specific immune tolerance or antigen-specific immunotherapy (ASI), is a promising approach to treat or prevent autoimmune disorders. Different optimization protocols (immunization routes, delivery systems, and approaches) are being developed to implement ASI against self-proteins. Including appropriate adjuvants, altered peptide ligand, and using multipeptides are approaches that can be used to specifically target autoimmunity. This review explores various ASI application methods, including different routes of antigen-specific sensitization, delivery systems, immunomodulators containing specific antigens, and other targeted approaches that have been successfully demonstrated to have therapeutic effects on autoimmune diseases.

Evaluation of METase-pemetrexed-loaded PEG-PLGA nanoparticles modified with anti-CD133-scFV for treatment of gastric carcinoma

PEG–PLGA nanoparticles (NPs) modified with anti-CD133 and tumor-targeting single-chain antibody fragment (scFV–NPs) for systemic delivery of methioninase (METase) and pemetrexed for gastric carcinoma were successfully formulated. The structure characterization and biological functions of METase-pemetrexed-loaded scFV–PEG–PLGA NPs (scFV–METase/pemetrexed–NPs) in vitro were investigated. Functional scFV–PEG–PLGA NPs or PEG–PLGA NPs present low cell cytoxicity in CD133+ SGC7901 cells. scFV–METase/pemetrexed–NPs (scFv–M/P–NP) was more effective in inhibiting tumor growth (including cell growth and migration ability) in CD133 positive expressed gastric cancer cells than METase/pemetrexed-NPs (M/P–NP). Moreover, METase enhanced the inhibitory effect of pemetrexed on thymidylate synthase (TS) synthesis and cell apoptosis. We have demonstrated the application of scFV-targeted PEG–PLGA NPs as a new potential strategy to enhance treatment benefits for gastric carcinoma.

Insulin-loaded PLGA microspheres for glucose-responsive release

Porous poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared, loaded with insulin, and then coated in poly(vinyl alcohol) (PVA) and a novel boronic acid-containing copolymer [poly(acrylamide phenyl boronic acid-co-N-vinylcaprolactam); p(AAPBA-co-NVCL)]. Multilayer microspheres were generated using a layer-by-layer approach depositing alternating coats of PVA and p(AAPBA-co-NVCL) on the PLGA surface, with the optimal system found to be that with eight alternating layers of each coating. The resultant material comprised spherical particles with a porous PLGA core and the pores covered in the coating layers. Insulin could successfully be loaded into the particles, with loading capacity and encapsulation efficiencies reaching 2.83 ± 0.15 and 82.6 ± 5.1% respectively, and was found to be present in the amorphous form. The insulin-loaded microspheres could regulate drug release in response to a changing concentration of glucose. In vitro and in vivo toxicology tests demonstrated that they are safe and have high biocompatibility. Using the multilayer microspheres to treat diabetic mice, we found they can effectively control blood sugar levels over at least 18 days, retaining their glucose-sensitive properties during this time. Therefore, the novel multilayer microspheres developed in this work have significant potential as smart drug-delivery systems for the treatment of diabetes.