Self-assembled nanoparticles of PLGA-conjugated glucosamine as a sustained transdermal drug delivery vehicle

Breast cancer cell targeting of L-leucine-PLGA conjugated hybrid solid lipid nanoparticles of betulin via L-amino acid transport system-1

The aim of fabricating hybrid solid lipid nanoparticles (HSLN) was to enhance the delivery of betulin to triple negative breast cancer cells through the intravenous route via L-amino transporter system-1, using L-leucine-PLGA conjugate (Conj-HSLN) by hot high pressure homogenisation method. Betulin (BN), having potent anticancer and antioxidant activity, faces challenges due to poor water solubility and permeability, affecting its bioavailability. The results revealed Conj-HSLN with particle size 318.3 ± 0.25 nm. The percent cumulative BN release from Conj-HSLN was 57.763%, 24h. The cytotoxicity study in MB-MDA-231 cell depicts, LD50 67.73 µg/ml in Conj-HSLN. Pharmacokinetics study reveals enhanced Cmax and half-life in Conj-HSLN (32.12 ± 0.25 µg/ml, 4.72 ± 0.53 h) than raw BN (1.31 ± 0.21 µg/ml, 7.54 ± 0.34 h). Enhanced distribution at tumour site (11.5967% ID, 2h) in Conj-HSLN signifies the role of L-leucine in the transport system. Pharmacodynamic study shows mean tumour volume of 765.3 ± 85.884, and 1450.01 ± 219.361 mm3 in Conj-HSLN, and BN, respectively, at 3rd week of treatment. Standardised uptake value attributed reduced glucose uptake, due to inhibited tumour growth and proliferation, confirmed by tumour biomarkers assay, VEGF and Caspase-9. In conclusion, the targeted controlled release L-leucine conjugated-BN loaded HSLN is stable, safe, and effective against triple negative breast cancers.

Progress and Challenges of Topical Delivery Technologies Meditated Drug Therapy for Osteoarthritis

Osteoarthritis (OA) is a degenerative disease commonly seen in middle-aged and elderly people. Multiple cytokines are involved in the local tissue damage in OA. Currently, non-pharmacologic and surgical interventions are the main conventional approaches for the treatment of OA. In terms of pharmaceutical drug therapy, NSAIDs and acetaminophen are mainly used to treat OA. However, it is prone to various adverse reactions such as digestive tract ulcer, thromboembolism, prosthesis loosening, nerve injury and so on. With the in-depth study of OA, more and more novel topical drug delivery strategies and vehicles have been developed, which can make up for the shortcomings of traditional dosage forms, improve the bioavailability of drugs, and significantly reduce drug side effects. This review summarizes the immunopathogenesis, treatment guidelines, and progress and challenges of topical delivery technologies of OA, with some perspectives on the future pharmacological treatment of OA proposed.

Recent Trends in Macromolecule-Based Approaches for Hair Loss Treatment

Macromolecules are large, complex molecules composed of smaller subunits known as monomers. The four primary categories of macromolecules found in living organisms are carbohydrates, lipids, proteins, and nucleic acids; they also encompass a broad range of natural and synthetic polymers. Recent studies have shown that biologically active macromolecules can help regenerate hair, providing a potential solution for current hair regeneration therapies. This review examines the latest developments in the use of macromolecules for the treatment of hair loss. The fundamental principles of hair follicle (HF) morphogenesis, hair shaft (HS) development, hair cycle regulation, and alopecia have been introduced. Microneedle (MN) and nanoparticle (NP) delivery systems are innovative treatments for hair loss. Additionally, the application of macromolecule-based tissue-engineered scaffolds for the in vitro and in vivo neogenesis of HFs is discussed. Furthermore, a new research direction is explored wherein artificial skin platforms are adopted as a promising screening method for hair loss treatment drugs. Through these multifaceted approaches, promising aspects of macromolecules for future hair loss treatments are identified.

The effect of Gd-DOTA locations within PLGA-b-PEG micelle encapsulated IR-1061 on bimodal over-1000 nm near-infrared fluorescence and magnetic resonance imaging

Multimodal imaging is attractive in biomedical research because it can provide multidimensional information about objects that individual techniques cannot accomplish. In particular, combining over one-thousand-nanometer near-infrared (OTN-NIR) fluorescence and magnetic resonance (MR) imaging is promising for detecting lesions with high sensitivity and structural information. Herein, we describe the development of a bimodal OTN-NIR/MRI probe from gadolinium-tetraazacyclododecanetetraacetic acid (Gd-DOTA) conjugated poly(lactic-co-glycolic acid)-block-poly(ethylene glycol) copolymer (PLGA-b-PEG) micelle encapsulated IR-1061 at two different locations. One configuration contains Gd-DOTA at the end of the PEG of the hydrophilic shell and the other contains Gd-DOTA at the border of PLGA/PEG. The two structures show remarkable differences in fluorescence and R₁ relaxation rates in biological environments; the structure with Gd-DOTA at the border of PLGA/PEG exhibits stable fluorescence and T₁ signal distribution in live mice. The introduction ratio of Gd-DOTA to PEG is significant for controlling the properties of both structures; a higher Gd-DOTA ratio is preferable for the contrast enhancement effect. We found that Gd-DOTA ratios higher than 10% degraded the fluorescence intensity when Gd-DOTA was bound to the end of PEG. In contrast, the introduction of 70% Gd-DOTA at the border of PLGA/PEG did not exhibit a degraded signal, and the structural stability was enhanced with higher ratios of Gd-DOTA. In conclusion, we confirmed that the location of Gd-DOTA is a crucial factor in designing high-performance probes. The overall properties improve when Gd-DOTA is set on the border of PLGA/PEG. These improvements in the properties by controlling the probe structures are promising for future biomedical applications.

Recent developments in natural and synthetic polymeric drug delivery systems used for the treatment of osteoarthritis

Osteoarthritis (OA), is a common musculoskeletal disorder that will progressively increase in older populations and is expected to be the most dominant cause of disability in the world population by 2030. The progression of OA is controlled by a multi-factorial pathway that has not been completely elucidated and understood yet. However, over the years, research efforts have provided a significant understanding of some of the processes contributing to the progression of OA. Both cartilage and bone degradation processes induce articular cells to produce inflammatory mediators that produce proinflammatory cytokines that block the synthesis of collagen type II and aggrecan, the major components of cartilage. Systemic administration and intraarticular injection of anti-inflammatory agents are the first-line treatments of OA. However, small anti-inflammatory molecules are rapidly cleared from the joint cavity which limits their therapeutic efficacy. To palliate this strong technological drawback, different types of polymeric materials such as microparticles, nanoparticles, and hydrogels, have been examined as drug carriers for the delivery of therapeutic agents to articular joints. The main purpose of this review is to provide a summary of recent developments in natural and synthetic polymeric drug delivery systems for the delivery of anti-inflammatory agents to arthritic joints. Furthermore, this review provides an overview of the design rules that have been proposed so far for the development of drug carriers used in OA therapy. Overall it is difficult to state clearly which polymeric platform is the most efficient one because many advantages and disadvantages could be pointed to both natural and synthetic formulations. That requires further research in the near future.

Human skin models: From healthy to disease-mimetic systems; characteristics and applications

Skin drug delivery is an emerging route in drug development, leading to an urgent need to understand the behaviour of active pharmaceutical ingredients within the skin. Given, As one of the body's first natural defences, the barrier properties of skin provide an obstacle to the successful outcome of any skin drug therapy. To elucidate the mechanisms underlying this barrier, reductionist strategies have designed several models with different levels of complexity, using non-biological and biological components. Besides the detail of information and resemblance to human skin in vivo, offered by each in vitro model, the technical and economic efforts involved must also be considered when selecting the most suitable model. This review provides an outline of the commonly used skin models, including healthy and diseased conditions, in-house developed and commercialized models, their advantages and limitations, and an overview of the new trends in skin-engineered models.

Polymeric nanoparticles based on carboxymethyl chitosan in combination with painless microneedle therapy systems for enhancing transdermal insulin delivery

Biodegradable nanoparticles (NPs) have been frequently used as insulin transdermal delivery vehicles due to their grand bioavailability, better encapsulation, controlled release and less toxic properties. However, the skin's barrier properties prevent insulin-loaded NP permeation at useful levels. Nowadays, microneedles have been spotlighted as novel transdermal delivery systems due to their advantages such as painlessness, efficient penetration and no hazardous residues. Herein, we introduce polymeric nanocarriers based on carboxymethyl chitosan (CMCS) for insulin delivery, combining with microneedle therapy systems, which can rapidly deliver insulin (INS) into the skin. The resulting CMCS-based nanocarriers are spherical nanoparticles with a mean size around 200 nm, which could generate supramolecular micelles to effectively encapsulate insulin (EE% = 83.78 ± 3.73%). A nanocrystalline microneedle array (6 × 6, 75/150 μm) was used to penetrate the stratum corneum (SC) for enhancing transdermal insulin delivery, while minimizing the pain sensation caused by intravenous injection. Compared with the transdermal rate of passive diffusion [2.77 ± 0.64 μg (cm-2 h-1)], the transdermal rate of the insulin-loaded NP combined with microneedle penetration shows a 4.2-fold increase [10.24 ± 1.06 μg (cm-2 h-1)] from permeation experiment in vitro. In vivo hypoglycemic experiments demonstrate the potential of using nanocarrier combination with microneedle arrays for painless insulin delivery through the skin in a clinical setting. Thus, the developed combination scheme of nanoparticles and microneedle arrays offers an effective, user-friendly, and low-toxicity option for diabetes patients requiring long-term and multiple treatments.

Transdermal delivery of Minoxidil using HA-PLGA nanoparticles for the treatment in alopecia

BACKGROUND

Alopecia has become a very common disease that many people around the world are suffered. Minoxidil (MXD) is the most well-known commercialized drug in its treatment. However, in the case of MXD administration, there are some problems with low efficiency of transdermal delivery and additional side effects.

METHOD

MXD and Rhodamine B (Rho B) are encapsulated in poly(Lactide-co-Glycolide) grafted hyaluronate nanoparticles (HA-PLGA/MXD NPs, HA-PLGA/Rho B NPs) which is prepared with W/O/W solvent evaporation method. After then, the investigation is carried out to confirm the feasibility of NPs in alopecia treatment.

RESULTS

Both of HA-PLGA/MXD NPs and HA-PLGA/Rho B NPs are successfully prepared. In addition, it is confirmed that HA-PLGA NPs sufficiently delivered to cells without any significant cytotoxicity by cell viability, cellular uptake and skin permeation test.

CONCLUSION

Taken together, HA-PLGA NPs as a transdermal delivery carrier to hair follicle cells can be exploited to develop the efficient and effective platform of transdermal drug delivery for the treatment of various diseases.

A Simple Non-Invasive Approach toward Efficient Transdermal Drug Delivery Based on Biodegradable Particulate System

Transdermal administration via skin appendages enables both localized and systemic drug delivery, as well as minimizes incidental toxicity. However, the design of an appropriate effective method for clinical use remains challenging. Here, we introduce calcium carbonate-based carriers for the transdermal transportation of bioactive substances. The proposed system presents easily manufacturable biodegradable particles with a large surface area enabling a high payload ability. Topical application of submicron porous CaCO₃ particles in rats followed by the therapeutic ultrasound treatment results in their deep penetration through the skin along with plentiful filling of the hair follicles. Exploiting the loading capacity of the porous particles, we demonstrate efficient transportation of a fluorescent marker along the entire depth of the hair follicle down the bulb region. In vivo monitoring of the carrier degradation reveals the active dissolution/recrystallization of CaCO₃ particles, resulting in their total resorption within 12 days. The proposed particulate system serves as an intrafollicular depot for drug storage and prolonged in situ release over this period. The urinary excretion profile proves the systemic absorption of the fluorescent marker. Hence, the elaborated transdermal delivery system looks promising for medical applications. The drug delivery to different target regions of the hair follicle may contribute to regenerative medicine, immunomodulation, and treatment of various skin disorders. In the meantime, the systemic uptake of the transported drug opens an avenue for prospective delivery routes beyond the scope of dermatology.

Two-Step Sustained-Release PLGA/Hyaluronic Acid Gel Formulation for Intra-articular Administration

In the development of drugs for intra-articular administration, sustained-release formulations are desirable because it is difficult to maintain the effect of conventional injections due to immediate drug leakage from the joint cavity. In this study, a sustained-release poly(lactic-co-glycolic acid) (PLGA) microsphere formulation for intra-articular administration containing indocyanine green (ICG) as a model drug was prepared to follow its fate after intra-articular administration in rats with a real-time in-vivo imaging system. ICG administered as an aqueous solution leaked from the joint cavity in a short time and was excreted outside the body within 1-3 d. However, ICG in the sustained-release formulation was retained in the joint cavity and released for 2 weeks. Next, a sustained-release formulation containing PLGA microspheres in a hyaluronic acid (HA) gel formulation was prepared. After gradual release in two stages, we could achieve sustained release for a longer period. It is considered that a combination formulation of PLGA microspheres and HA gel can significantly improve the sustained release of a drug administered into the knee joint.

Sodium alginate nanoparticles as a new transdermal vehicle of glucosamine sulfate for treatment of osteoarthritis

Glucosamine sulfate (GS) has been used orally for the treatment of osteoarthritis (OA). However, it may be susceptible to the liver first pass phenomenon, which greatly affects its bioavailability, in addition to its side effects on the gastrointestinal tract. Alginate nanoparticles (Alg NPs) were investigated as a new drug carrier for transdermal delivery of GS to improve its effectiveness and reduce side effects. GS-Alg NPs were characterized by encapsulation efficiency, NP yield, particle size and surface charge properties. The in vitro release studies of GS and the ex vivo permeability through rat skin were determined using a UV-Vis spectrophotometer. GS-Alg NPs are within the nanometer range of size. High negative surface charge values are obtained and indicate the high suspension stability of the prepared formulation. The in vitro release studies showed that GS is released from Alg NPs in a sustained and prolonged manner. The ex vivo permeability of GS through rat skin is enhanced significantly after encapsulation in the negatively charged Alg NPs. We successfully reported a highly stable nanoparticlulate system using Alg NPs that permits the encapsulation of GS for topical administration, overcoming the disadvantages of oral administration.

Enhanced chondrogenic differentiation of stem cells using an optimized electrospun nanofibrous PLLA/PEG scaffolds loaded with glucosamine

Recently, tissue engineering has become one of the most important approaches in medical research for the treatment of injuries and lesions. In the present study, poly(l‐lactide) acid (PLLA), and polyethylene glycol (PEG) with different ratios and PEG molecular weights were used in order to produce appropriate nanofibrous scaffolds using the electrospinning technique for cartilage tissue engineering applications. Glucosamine was also incorporated into the polymeric scaffolds to enhance the biological properties. Mesenchymal stem cells and chondrocytes were used to monitor the differentiation yield. Water absorption test, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay, real‐time reverse transcription polymerase chain reaction and mechanical properties analyses were performed to characterize the prepared scaffolds. All fabricated scaffolds had porous and nanofibrous structure with interconnected pores. The PLLA‐PEG scaffolds containing PEG with the molecular weights of 3000 and 20,000 and ratio of 85:15 was selected for glucosamine incorporation and cell culture studies due to their superior mechanical properties. According to our data, it was identified that PLLA/PEG 20,000 containing glucosamine had the most capability to support protein absorption, stem cell attachment, and proliferation. Chondrogenic‐related genes such as sex‐determining region Y‐Box 9 (SOX9) and collagen type II were shown to be expressed on these scaffolds higher than those observed on control groups. Taking together, it was demonstrated that in combination with PLLA, PEG 20,000 is a suitable substrate to improve the mechanical and physical properties of nanofibrous scaffolds. In addition, glucosamine‐PLLA/PEG 20,000 was shown to support stem cell attachment, proliferation, and chondrogenic differentiation and so holds promising potential for cartilage tissue engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2461–2474, 2017.

Preparation, Physicochemical Characterization and Anti-fungal Evaluation of Nystatin-Loaded PLGA-Glucosamine Nanoparticles

PURPOSE

Nystatin loaded PLGA and PLGA-Glucosamine nanoparticles were formulated. PLGA were functionalized with Glucosamine (PLGA-GlcN) to enhance the adhesion of nanoparticles to Candida Albicans (C.albicans) cell walls.

METHOD

Quasi-emulsion solvent diffusion method was employed using PLGA and PLGA-GlcN with various drug-polymer ratios for the preparation of nanoparticles. The nanoparticles were evaluated for size, zeta potential, polydispersity index, drug crystallinity, loading efficiency and release properties. DSC, SEM, XRPD, ¹H-NMR, and FT-IR were performed to analyze the physicochemical properties of the nanoparticles. Antifungal activity of the nanoparticles was evaluated by determination of MICs against C.albicans.

RESULTS

The spectra of ¹H-NMR and FT-IR analysis ensured GlcN functionalization on PLGA nanoparticles. SEM characterization confirmed that particles were in the nanosize range and the particle size for PLGA and PLGA-GlcN nanoparticles were in the range of 108.63 ± 4.5 to 168.8 ± 5.65 nm and 208.76 ± 16.85 nm, respectively. DSC and XRPD analysis ensured reduction of the drug crystallinity in the nanoparticles. PLGA-GlcN nanoparticles exhibit higher antifungal activity than PLGA nanoparticles.

CONCLUSION

PLGA-GlcN nanoparticles showed more antifungal activity with appropriate physicochemical properties than pure Nystatin and PLGA nanoparticles.

In vitro skin models as a tool in optimization of drug formulation

(Trans)dermal drug therapy is gaining increasing importance in the modern drug development. To fully utilize the potential of this route, it is important to optimize the delivery of active ingredient/drug into/through the skin. The optimal carrier/vehicle can enhance the desired outcome of the therapy therefore the optimization of skin formulations is often included in the early stages of the product development. A rational approach in designing and optimizing skin formulations requires well-defined skin models, able to identify and evaluate the intrinsic properties of the formulation. Most of the current optimization relies on the use of suitable ex vivo animal/human models. However, increasing restrictions in use and handling of animals and human skin stimulated the search for suitable artificial skin models. This review attempts to provide an unbiased overview of the most commonly used models, with emphasis on their limitations and advantages. The choice of the most applicable in vitro model for the particular purpose should be based on the interplay between the availability, easiness of the use, cost and the respective limitations.

PLGA: a unique polymer for drug delivery

Biodegradable polymers have played an important role in the delivery of drugs in a controlled and targeted manner. Polylactic-co-glycolic acid (PLGA) is one of the extensively researched synthetic biodegradable polymers due to its favorable properties. It is also known as a ‘Smart Polymer’ due to its stimuli sensitive behavior. A wide range of PLGA-based drug delivery systems have been reported for the treatment or diagnosis of various diseases and disorders. The present review provides an overview of the chemistry, physicochemical properties, biodegradation behavior, evaluation parameters and applications of PLGA in drug delivery. Different drug–polymer combinations developed into drug delivery or carrier systems are enumerated and discussed.