Polymer based microspheres of aceclofenac as sustained release parenterals for prolonged anti-inflammatory effect

Effect of poly(ε-caprolactone) microspheres on population pharmacokinetic/pharmacodynamic model of a simple coumarin

This study aims to evaluated the impact of poly(ε-caprolactone) (PCL) microspheres on the pharmacokinetics and pharmacodynamics (PopPK/PD) of 6-methylcoumarin (6MC). For this, PCL microspheres loaded with 6MC were prepared using the emulsification-evaporation method. Particle size, zeta potential, drug loading, and entrapment efficiency were characterised by dynamic light scattering and UV spectrophotometry. In vitro release and pharmacokinetics in Wistar rats were assessed for free and encapsulated 6MC. Anti-inflammatory activity was evaluated using the carrageenan-induced paw edoema model, with PopPK and PopPK/PD models developed. Microspheres showed diameters between 2.9 and 7.1 µm, zeta potentials of -10 to -15 mV, and drug loading of 0.24 mg/mg. Encapsulation efficiency was 45.5% to 75.9%. PopPK models showed enhanced absorption and distribution, with increased anti-inflammatory potency of encapsulated 6MC. PCL microspheres significantly improved the pharmacokinetic and pharmacodynamic profiles of 6MC, enhancing its therapeutic potential for lipophilic drugs.

Recent advancements in microspheres mediated targeted delivery for therapeutic interventions in osteoarthritis

Osteoarthritis (OA), affecting around 240 million people globally is a major threat. Currently, available drugs only treat the symptoms of OA; they cannot reverse the disease's progression. The delivery of drugs to afflicted joints is challenging because of poor vasculature of articular cartilage results in their less bioavailability and quick elimination from the joints. Recently approved drugs such as KGN and IL-1 receptor antagonists also encounter challenges because of inadequate formulations. Therefore, microspheres could be a potential player for the intervention of OA owing to its excellent physicochemical properties. This review primarily focuses on microspheres of distinct biomaterials acting as cargo for drugs and biologicals via different delivery routes in the effective management of OA. Microspheres can improve the efficacy of therapeutics by targeting strategies at specific body locations. This review also highlights clinical trials conducted in the last few decades.

Enhancing periodontal defences with nanofiber treatment: recent advances and future prospects

The term periodontal disease is used to define diseases characterised by inflammation and regeneration of the gums, cementum, supporting bone, and periodontal ligament. The conventional treatment involves the combination of scaling, root planning, and surgical approaches which are invasive and can pose certain challenges. Intrapocket administration of nanofibers can be used for overcoming challenges which can help in speeding up the wound repair process and can also be used to promote osteogenesis. To help make drug delivery more effective, nanofibers are an interesting solution. Nanofibers are nanosized 3D structures that can fill the pockets and have excellent mucoadhesion which prolongs their retention time on the target site. Moreover, their structure mimics the natural extracellular matrix which enables nanomaterials to sense local biological conditions and start cellular-level reprogramming to produce the necessary therapeutic efficacy. In this review, the significance of intrapocket administration of nanofibers using recent research for the management of periodontitis has been discussed in detail. Furthermore, we have discussed polymers used for the preparation of nanofibers, nanofiber production methods, and the patents associated with these developments. This comprehensive compilation of data serves as a valuable resource, consolidating recent developments in nanofiber applications for periodontitis management into one accessible platform.

Recent advances in polymeric microparticle-based drug delivery systems for knee osteoarthritis treatment

Due to the poor bioavailability and high joint clearance of drugs, sustained delivery of therapeutic agents has proven difficult in the treatment of osteoarthritis (OA). Intra-articular (IA) drug delivery strategy is an attractive option for enhancing OA patients' prognosis, for which various polymer materials have been used as drug carriers due to their attractive delivery properties, to slow or even reverse the progress of OA by prolonging the duration of therapeutic agent residence in the joint. This article focuses on the recent developments in natural and synthetic polymer-based microsphere drug delivery systems for treating knee osteoarthritis. It evaluates the translational potential of some novel formulations for clinical application.

Evaluation and Application of Silk Fibroin Based Biomaterials to Promote Cartilage Regeneration in Osteoarthritis Therapy

Osteoarthritis (OA) is a common joint disease characterized by cartilage damage and degeneration. Traditional treatments such as NSAIDs and joint replacement surgery only relieve pain and do not achieve complete cartilage regeneration. Silk fibroin (SF) biomaterials are novel materials that have been widely studied and applied to cartilage regeneration. By mimicking the fibrous structure and biological activity of collagen, SF biomaterials can promote the proliferation and differentiation of chondrocytes and contribute to the formation of new cartilage tissue. In addition, SF biomaterials have good biocompatibility and biodegradability and can be gradually absorbed and metabolized by the human body. Studies in recent years have shown that SF biomaterials have great potential in treating OA and show good clinical efficacy. Therefore, SF biomaterials are expected to be an effective treatment option for promoting cartilage regeneration and repair in patients with OA. This article provides an overview of the biological characteristics of SF, its role in bone and cartilage injuries, and its prospects in clinical applications to provide new perspectives and references for the field of bone and cartilage repair.

Impact of porous microsponges in minimizing myotoxic side effects of simvastatin

Simvastatin (SV) is a poorly soluble drug; its oral administration is associated with a significant problem: Myopathy. The present study aims to formulate SV microsponges that have the potential to minimize the myotoxicity accompanying the oral administration of the drug. SV microsponges were prepared by exploiting the emulsion solvent evaporation technique. The % entrapment efficiency (%EE) of the drug approached 82.54 ± 1.27%, the mean particle size of SV microsponges ranged from 53.80 ± 6.35 to 86.03 ± 4.79 µm in diameter, and the % cumulative drug release (%CDR) of SV from microsponges was significantly higher than that from free drug dispersion much more, the specific surface area of the optimized microsponges formulation was found to be 16.6 m²/g revealed the porosity of prepared microsponges. Histological and glycogen histochemical studies in the skeletal muscles of male albino rats revealed that microsponges were safer than free SV in minimizing myotoxicity. These findings were proven by Gene expression of Mitochondrial fusion and fission (Mfn1) & (Fis1) and (Peroxisome proliferator-activated receptor gamma co-activator 1α) PGC-1α. Finally, our study ascertained that SV microsponges significantly decreased the myotoxicity of SV.

Investigating the Targeting Power to Brain Tissues of Intranasal Rasagiline Mesylate-Loaded Transferosomal In Situ Gel for Efficient Treatment of Parkinson's Disease

Rasagiline mesylate (RSM) is a hydrophilic drug with poor oral bioavailability (36%) because of hepatic first-pass metabolism. The present study focuses on delivering RSM directly to the brain through its inclusion within transferosomal in situ gel administered through the intranasal (IN) route. Transferosomes were formed by the thin-film hydration method with the aid of Design-Expert^® software by varying the edge activator (EA) type in the absence or presence of cholesterol. By desirability calculations, the optimum formulation was composed of phosphatidylcholine and sodium deoxycholate as an EA (5:1% w/w) with no cholesterol. The optimum formulation was 198.63 ± 34.98 nm in size and displayed an entrapment efficiency of 95.73 ± 0.09%. Transmission electron microscopy revealed discrete and spherical vesicles. Optimized transferosomes were further incorporated into an in situ gel composed of 0.5% pectin, 15% Pluronic^® F-127, and 5% Pluronic^® F-68 and tested for the in vivo performance. The systemic as well as brain kinetics were assessed in rats by comparing the IN-administered in situ gel to the IV aqueous solution. The optimum in situ gel showed safety and biocompatibility on rats' nasal mucosa with enhanced brain bioavailability (131.17%). Drug targeting efficiency and direct transport percentage indices (304.53% and 67.16%, respectively) supported successful brain targeting offering direct nose-to-brain drug delivery.

Enzymatic PCL-grafting to NH2-end grouped silica and development of microspheres for pH-stimulated release of a hydrophobic model drug

This study set out to evaluate novel PCL-based silica containing nanohybrids as the polymer matrix in a hydrophobic drug-loaded microsphere system. Nanohybrids were synthesized by PCL-grafting to NH₂-end grouped silica by in situ enzymatic ring opening polymerization of ε-caprolactone. Molecular weight and monomer conversion, PCL grafting percentage, thermal properties and crystallinity of the nanohybrids were determined by ¹H NMR, TGA, DSC and XRD. Synthesized nanohybrids had low crystallinity percentage (32 and 39 %) and molecular weight (4800 and 8700 g/mol), promising for controlled drug release applications. The nanohybrids were used for fabrication of trans-chalcone-loaded microspheres by O/W single emulsion solvent evaporation. Mean particle diameter of the microspheres were between 15 and 30 µm. The result of release studies showed that optimum microsphere formulations (AP4 and A2, respectively) had 61 and 64 % encapsulation efficiency. One of the more significant findings to emerge from this investigation is that TC release was extended to 16 and 37 days, in a controlled manner. TC release was significantly enhanced in acidic pH media (pH 3.6 and 5.6) indicating pH-dependent release from nanohybrid microspheres; releasing 80-100 % of the loaded drug in 4-14 days. Drug/polymer interactions and molecular structures were investigated by FT-IR spectroscopy and DSC analysis. According to the results obtained, enzymatically synthesized nanohybrids have potential for pH-dependent release of the model drug, trans-chalcone.

The Role of Polymeric Biomaterials in the Treatment of Articular Osteoarthritis

Osteoarthritis is a high-prevalence joint disease characterized by the degradation of cartilage, subchondral bone thickening, and synovitis. Due to the inability of cartilage to self-repair, regenerative medicine strategies have become highly relevant in the management of osteoarthritis. Despite the great advances in medical and pharmaceutical sciences, current therapies stay unfulfilled, due to the inability of cartilage to repair itself. Additionally, the multifactorial etiology of the disease, including endogenous genetic dysfunctions and exogenous factors in many cases, also limits the formation of new cartilage extracellular matrix or impairs the regular recruiting of chondroprogenitor cells. Hence, current strategies for osteoarthritis management involve not only analgesics, anti-inflammatory drugs, and/or viscosupplementation but also polymeric biomaterials that are able to drive native cells to heal and repair the damaged cartilage. This review updates the most relevant research on osteoarthritis management that employs polymeric biomaterials capable of restoring the viscoelastic properties of cartilage, reducing the symptomatology, and favoring adequate cartilage regeneration properties.

Drug-releasing Microspheres for Stem Cell Differentiation

The ability of stem cells to differentiate into specialized cells make them a valuable tool for therapeutic applications. 3D bioprinting, a subset of additive manufacturing, uses bioinks composed of cells and biomaterials to create living tissues. The use of bioactive factors like small molecules and proteins can promote stem cell differentiation into the desired cell phenotypes for tissue regeneration. Small molecules can accelerate the process of regeneration in tissue engineering, maintain bioactivity in a biological environment, and minimize the costs associated with this process. Additionally, they can be encapsulated in specialized drug-delivery devices called microspheres for controlled release. Microspheres are small (1-1000 μm) spherical particles usually made from biodegradable and biocompatible polymers that can be loaded with drugs and other bioactive components. They can then be integrated into stem-cell-laden bioinks used to form bioprinted tissues, where they will release the encapsulated drug and promote differentiation of stem cells into the desired mature cell type. Microspheres can be widely used to encapsulate a broad range of therapeutic agents, including hydrophilic and hydrophobic small molecule drugs, DNA, and proteins. The release of encapsulated molecules occurs through degradation and erosion of the polymer matrix. This article provides detailed protocols for fabricating and sterilizing drug-releasing microspheres made from poly-ε-caprolactone, a promising biodegradable polymer often used for controlled drug delivery due to its biocompatibility and biodegradation kinetics. Additional protocols describe characterization of the loading and size of microspheres as well as incorporation of microspheres into a fibrin-based bioink for 3D bioprinting. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Fabrication of drug-releasing PCL microspheres Support Protocol 1: Preparation of microspheres for determination of encapsulation efficiency by HPLC Support Protocol 2: Preparation of microspheres for SEM analysis Basic Protocol 2: Incorporation of microspheres into fibrin-based bioink.

Chemically-Induced Cross-Linking of Peptidic Fibrils for Scaffolding Polymeric Particles and Macrophages

EAK16-II (EAK) is a self-assembling peptide (SAP) that forms β-sheets and β-fibrils through ionic-complementary interactions at physiological ionic strengths. The soft materials can be injected in vivo, creating depots of drugs and cells for rendering pharmacological and biological actions. The scope of the applications of EAK is sought to extend to tissues through which the flow of extracellular fluid tends to be limited. In such anatomical locales the rate and extent of the fibrilization are limited insofar as drug delivery and cellular scaffolding would be impeded. A method is generated utilizing a carbodiimide cross-linker by which EAK fibrils are pre-assembled yet remain injectable soft materials. It is hypothesized that the resulting de novo covalent linkages enhance the stacking of the β-sheet bilayers, thereby increasing the lengths of the fibrils and the extent of their cross-linking, as evidenced in Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy, scanning electron microscopy, and atomic force microscopy analyses. The cross-linked EAK (clEAK) retains polymeric microspheres with an average diameter of 1 µm. Macrophages admixed with clEAK remain viable and do not produce the inflammatory mediator interleukin-1β. These results indicate that clEAK should be investigated further as a platform for delivering particles and cells in vivo.

Recent Advances in Antiinflammatory Material Design

Implants and prostheses are widely used to replace damaged tissues or to treat various diseases. However, besides the risk of bacterial or fungal infection, an inflammatory response usually occurs. Here, recent progress in the field of anti-inflammatory biomaterials is described. Different materials and approaches are used to decrease the inflammatory response, including hydrogels, nanoparticles, implant surface coating by polymers, and a variety of systems for anti-inflammatory drug delivery. Complex multifunctional systems dealing with inflammation, microbial infection, bone regeneration, or angiogenesis are also described. New promising stimuli-responsive systems, such as pH- and temperature-responsive materials, are also being developed that would enable an "intelligent" antiinflammatory response when the inflammation occurs. Together, different approaches hold promise for creation of novel multifunctional smart materials allowing better implant integration and tissue regeneration.

Long Acting Polycaprolactone Based Parenteral Formulation of Aripiprazole Targeting Behavioural and Biochemical Deficit in Schizophrenia

Schizophrenia is a neurodevelopmental disorder which is expressed in the form of disturbed behaviour and abnormal mental functions. Patient's non-adherence to the medicine is the main cause of failure of drug therapy and increases incidence of relapses. Thus, for successful management of disease long acting parenteral formulations were developed. Aripiprazole was encapsulated in biocompatible polycaprolactone microsphere by o/w emulsion solvent-evaporation method in order to achieve sustained release of the drug for several weeks after single subcutaneous administration. They were optimised on the basis of various parameters such as physical appearance, particle size (49.4 μm-387.1 μm), encapsulation efficiency (70%-95%), percentage yield (33%-75%) and drug loading (25.9%-47.5%). The surface topography and sphericity of the microspheres was determined by scanning electron microscopy which revealed that the microspheres formed were spherical and non-porous in nature. The in vitro releases from the selected formulations were found to be 87% and 95% respectively after 45 days of dissolution. In vivo efficacy of optimised formulation showed significantly (p < 0.05) amelioration of various positive, negative and cognitive symptoms associated with schizophrenia and oxidative stress markers in ketamine-induced schizophrenia model in rats for 30 days.

Degradable, thermo-, pH- and redox-sensitive hydrogel microcapsules for burst and sustained release of drugs

Polymer microcapsules offer a possibility of storing increased amounts of drugs. Appropriate design and composition of the microcapsules allow tuning of the drug-release process. In this paper, we report on synthesis of hydrogel microcapsules sensitive to temperature and pH and degradable by glutathione and hydrogen peroxide. Microcapsules were based on thermo-responsive poly(N-isopropylacrylamide) and degradable cystine crosslinker, and were synthesized by applying precipitation polymerization. Such way of polymerization was appropriately modified to limit the crosslinking in the microcapsule center. This led to a possibility of washing out the pNIPA core at room temperature and the formation of a capsule. Microcapsules revealed rather high drug-loading capacity of ca. 17%. The degradation of the microcapsules by the reducing agent (GSH) and the oxidizing agent (H₂O₂) was confirmed by using the DLS, UV-Vis, SEM and TEM techniques. Depending on pH and concentration of the reducing/oxidizing agents a fast or slow degradation of the microcapsules and a burst or long-term release of doxorubicin (DOX) were observed. The DOX loaded microcapsules appeared to be cytotoxic against A2780 cancer cells similarly to DOX alone, while unloaded microcapsules did not inhibit proliferation of the cells.