Advanced trends in protein and peptide drug delivery: a special emphasis on aquasomes and microneedles techniques

Therapeutic Potential of Microneedle Assisted Drug Delivery for Wound Healing: Current State of the Art, Challenges, and Future Perspective

Microneedles (MNs) appear as a transformative and minimally invasive platform for transdermal drug delivery, representing a highly promising strategy in wound healing therapeutics. This technology, entailing the fabrication of micron-scale needle arrays, enables the targeted and efficient delivery of bioactive agents into the epidermal and dermal layers without inducing significant pain or discomfort. The precise penetration of MNs facilitates localized and sustained drug release, which significantly enhances tissue regeneration and accelerates wound closure. Furthermore, MNs can be engineered to encapsulate essential bioactive compounds, including antimicrobial agents, growth factors, and stem cells, which are critical for modulating the wound healing cascade and mitigating infection risk. The biodegradable nature of these MNs obviates the need for device removal, rendering them particularly advantageous in the management of chronic wounds such as diabetic ulcers and pressure sores. The integration of nanotechnology within MNs further augments their drug-loading capacity, stability, and controlled-release kinetics, offering a sophisticated therapeutic modality. This cutting-edge approach has the potential to redefine wound care by optimizing therapeutic efficacy, reducing adverse effects, and enhancing patient adherence. As MN technology advances, its application in wound healing exemplifies a dynamic frontier within biomedical engineering and regenerative medicine.

Design and optimization of chitosan-coated solid lipid nanoparticles containing insulin for improved intestinal permeability using piperine

The objective of this research was to optimize the composition and performance of chitosan-coated solid lipid nanoparticles carrying insulin (Ch-In-SLNs) and to assess the potential of piperine in enhancing the intestinal permeability of insulin from these SLNs in vitro. The SLNs were formulated from glyceryl behenate (GB), soya lecithin, and poloxamer® 407, and then coated with a combination of chitosan and piperine to facilitate insulin penetration across the gastrointestinal (GI) mucosa. A Box-Behnken Design (BBD) was utilized to optimize the Ch-In-SLNs formulations, with PDI, particle size, zeta potential, and association efficiency (AE) serving as the response variables. The resulting Ch-In-SLNs exhibited excellent monodispersity (PDI = 0.4), optimal particle size (654.43 nm), positive zeta potential (+36.87 mV), and low AE values. The Ch-In-SLNs demonstrated sustained release of insulin for 12 h in simulated gastric fluid (SGF) and intestinal fluid (SIF), with increased release in the latter. After incubation in SGF and SIF for 12 h, the insulin SLNs retained 54 and 41 % of their initial insulin load, respectively, indicating effective protection from gastric enzymes. Permeation studies using goat intestine and Caco-2 cell lines indicated improved insulin permeation in the presence of piperine. Additionally, cell uptake studies confirmed the role of piperine in enhancing insulin permeation.

Advances in Transdermal Delivery of Antimicrobial Peptides for Wound Management: Biomaterial-Based Approaches and Future Perspectives

Antimicrobial peptides (AMPs), distinguished by their cationic and amphiphilic nature, represent a critical frontier in the battle against antimicrobial resistance due to their potent antimicrobial activity and a broad spectrum of action. However, the clinical translation of AMPs faces hurdles, including their susceptibility to degradation, limited bioavailability, and the need for targeted delivery. Transdermal delivery has immense potential for optimizing AMP administration for wound management. Leveraging the skin's accessibility and barrier properties, transdermal delivery offers a noninvasive approach that can circumvent systemic side effects and ensure sustained release. Biomaterial-based delivery systems, encompassing nanofibers, hydrogels, nanoparticles, and liposomes, have emerged as key players in enhancing the efficacy of transdermal AMP delivery. These biomaterial carriers not only shield AMPs from enzymatic degradation but also provide controlled release mechanisms, thereby elevating stability and bioavailability. The synergistic interaction between the transdermal approach and biomaterial-facilitated formulations presents a promising strategy to overcome the multifaceted challenges associated with AMP delivery. Integrating advanced technologies and personalized medicine, this convergence allows the reimagining of wound care. This review amalgamates insights to propose a pathway where AMPs, transdermal delivery, and biomaterial innovation harmonize for effective wound management.

Review on novel targeted enzyme drug delivery systems: enzymosomes

The goal of this review is to present enzymosomes as an innovative means for site-specific drug delivery. Enzymosomes make use of an enzyme's special characteristics, such as its capacity to accelerate the reaction rate and bind to a particular substrate at a regulated rate. Enzymosomes are created when an enzyme forms a covalent linkage with a liposome or lipid vesicle surface. To construct enzymosomes with specialized activities, enzymes are linked using acylation, direct conjugation, physical adsorption, and encapsulation techniques. By reducing the negative side effects of earlier treatment techniques and exhibiting efficient medication release, these cutting-edge drug delivery systems improve long-term sickness treatments. They could be a good substitute for antiplatelet medication, gout treatment, and other traditional medicines. Recently developed supramolecular vesicular delivery systems called enzymosomes have the potential to improve drug targeting, physicochemical characteristics, and ultimately bioavailability in the pharmaceutical industry. Enzymosomes have advantages over narrow-therapeutic index pharmaceuticals as focusing on their site of action enhances both their pharmacodynamic and pharmacokinetic profiles. Additionally, it reduces changes in normal enzymatic activity, which enhances the half-life of an enzyme and accomplishes enzyme activity on specific locations.

Biomaterials for Protein Delivery: Opportunities and Challenges to Clinical Translation

The development of biomaterials for protein delivery is an emerging field that spans materials science, bioengineering, and medicine. In this review, we highlight the immense potential of protein-delivering biomaterials as therapeutic options and discuss the multifaceted challenges inherent to the field. We address current advancements and approaches in protein delivery that leverage stimuli-responsive materials, harness advanced fabrication techniques like 3D printing, and integrate nanotechnologies for greater targeting and improved stability, efficacy, and tolerability profiles. We also discuss the demand for highly complex delivery systems to maintain structural integrity and functionality of the protein payload. Finally, we discuss barriers to clinical translation, such as biocompatibility, immunogenicity, achieving reliable controlled release, efficient and targeted delivery, stability issues, scalability of production, and navigating the regulatory landscape for such materials. Overall, this review summarizes insights from a survey of the current literature and sheds light on the interplay between innovation and the practical implementation of biomaterials for protein delivery.

Formulation, optimization and full characterization of mirtazapine loaded aquasomes: a new technique to boost antidepressant effects

OBJECTIVE

The development of Mirtazapine (MRT)-loaded aquasomes by co-precipitation sonication technique to boost the antidepressant potential of MRT.

METHODOLOGY

MRT-loaded aquasomes formulations were prepared using Box-Behnken design to investigate the effect of independent factors including sonication time (X1), sonication temperature (X2), and sugar concentration (X3) on the dependent variables as particle size and drug loading efficiency. The formulation of the optimized formula was verified by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and X-ray Powder Diffraction (XRPD). Furthermore, the morphology of the formula was evaluated by Transmission Electron Microscopy (TEM). The optimum MRT- loaded aquasomes was assessed for physiochemical properties, in vitro MRT release and in vivo antidepressant effects in mice model.

RESULTS

The results revealed that the optimized formula showed a small particle size of 202.7 ± 3.7 nm and a high loading efficiency of 77.65 ± 2.6%. Thermal DSC and XRPD studies demonstrated the amorphous nature of MRT-loaded aquasomes. The in vitro study demonstrated sustained release of F (opt) 88.16% after 8 h, compared with plain MRT release of 63.06% after 1 h. Mice treated with MRT-loaded aquasomes demonstrated reduced immobility time in behavioral analysis to 37% with MRT-loaded aquasomes, while plain MRT reduced it to 55%.

CONCLUSION

These results confirmed that the antidepressant effect of MRT was significantly boosted in formulated aquasomes, and thereby they provide a promising carrier nano vesicular system for effective delivery of MRT.

Recent advances in delivery of transdermal nutrients: A review

Nutrients provide vital functions in the body for sustained health, which have been shown to be related to the incidence, prevention and treatment of disease. However, limited bioavailability, loss of targeting specificity and the increased hepatic metabolism limit the utilization of nutrients. In this review, we highlight transdermal absorption of nutrients, which represents an opportunity to allow great use of many nutrients with promising human health benefits. Moreover, we describe how the various types of permeation enhancers are increasingly exploited for transdermal nutrient delivery. Chemical penetration enhancers, carrier systems and physical techniques for transdermal nutrient delivery are described, with a focus on combinatorial approaches. Although there are many carrier systems and physical techniques currently in development, with some tools currently in advanced clinical trials, relatively few products have achieved full translation to clinical practice. Challenges and further developments of these tools are discussed here in this review. This review will be useful to researchers interested in transdermal applications of permeation enhancers for the efficient delivery of nutrients, providing a reference for supporting the need to take more account of specific nutritional needs in specific states.

Synthesis and Characterization of Baicalein-loaded Aquasomes: An In vitro and In silico Perspective for Diabetes Mellitus

BACKGROUND

Millions of individuals worldwide suffer from metabolic abnormalities induced by diabetes. Baicalein, a flavonoid, has shown several properties in various treatments with potential properties, including anti-inflammatory, antioxidant, and anti-diabetic properties. Practically, its application is hindered due to low solubility in aqueous media. Overcoming this challenge, aquasomes can offer an effective approach for delivering drugs and bioactive molecules to target various diseases.

OBJECTIVE

The study aimed to develop and evaluate baicalein-loaded aquasomes for improving solubility and comparing their antidiabetic properties to acarbose through in silico docking.

METHODS

Baicalein-loaded aquasomes were prepared through a three-step process: core preparation, lactose coating, and drug loading. The evaluation included assessing particle size, drug-excipient interactions, drug entrapment efficiency, loading capacity, in vitro drug release, and the kinetics of drug release. In silico docking and in vitro α-amylase inhibition activity was evaluated to assess the anti-diabetic potential of baicalein.

RESULTS

The baicalein-loaded aquasomes were spherical with sizes ranging from 300-400 nm. FTIR analysis indicated no interaction between the components. The formulation exhibited drug entrapment efficiency of 94.04±0 4.01% and drug loading of 17.60 ± 01.03%. Drug release study showed sustained and complete (97.30 ± 02.06%) release, following first-order kinetics. Docking analysis revealed comparable binding affinity to acarbose, while the α-amylase inhibition assay showed greater inhibition potential of the aquasomes compared to the baicalein solution.

CONCLUSION

Aquasomes offer an alternative approach to conventional delivery methods. The selfassembling characteristics of aquasomes greatly simplify their preparation process, adding to their appeal as a drug delivery system.

Peptide-containing nanoformulations: Skin barrier penetration and activity contribution

Transdermal drug delivery presents a less invasive pathway, circumventing the need to pass through the gastrointestinal tract and liver, thereby reducing drug breakdown, initial metabolism, and gastrointestinal discomfort. Nevertheless, the unique composition and dense structure of the stratum corneum present a significant barrier to transdermal delivery. This article presents an overview of the current developments in peptides and nanotechnology to address this challenge. Initially, we sum up peptide-containing nanoformulations for transdermal drug delivery, examining them through the lenses of both inorganic and organic materials. Particular emphasis is placed on the diverse roles that peptides play within these nanoformulations, including conferring functionality upon nanocarriers and enhancing the biological efficacy of drugs. Subsequently, we summarize innovative strategies for enhancing skin penetration, categorizing them into passive and active approaches. Lastly, we discuss the therapeutic potential of peptide-containing nanoformulations in addressing a range of diseases, drawing insights from the biological activities and functions of peptides. Furthermore, the challenges hindering clinical translation are also discussed, providing valuable insights for future advancements in transdermal drug delivery.

Stimuli-Responsive Hydrogels for Protein Delivery

Proteins and peptides are potential therapeutic agents, but their physiochemical properties make their use as drug substances challenging. Hydrogels are hydrophilic polymeric networks that can swell and retain high amounts of water or biological fluids without being dissolved. Due to their biocompatibility, their porous structure, which enables the transport of various peptides and proteins, and their protective effect against degradation, hydrogels have gained prominence as ideal carriers for these molecules' delivery. Particularly, stimuli-responsive hydrogels exhibit physicochemical transitions in response to subtle modifications in the surrounding environment, leading to the controlled release of entrapped proteins or peptides. This review is focused on the application of these hydrogels in protein and peptide delivery, including a brief overview of therapeutic proteins and types of stimuli-responsive polymers.

Lecithin Reverse Micelle System is Promising in Constructing Carrier Particles for Protein Drugs Encapsulated Pressurized Metered‐Dose Inhalers

Protein drugs contained within pressurized metered dose inhalers (pMDIs) show immense potential for fundamental research and industrial applications, owing to their high bioavailability, convenient administration, and cost‐effectiveness. To deliver protein drugs efficiently, researchers have reached a consensus on the use of carrier particles. However, the main obstacle impeding the commercial availability of pMDI carrier particles is their low stability. This instability is primarily attributed to particle aggregation caused by the Ostwald ripening phenomenon and chemical degradation by water sensitivity of protein drugs. This study proposes the utilization of lecithin, a carrier material possessing an amphiphilic structure, to overcome this bottleneck. By constructing lecithin‐based reverse micelle systems with protein drugs encapsulated within the high‐polarity microdomain, this work anticipates an improvement in the stability of carrier particles within pMDIs. Specifically, the formation of crystalline phases in the reverse micelle systems can control carrier particle size through crystalline self‐limiting effect, preventing particle aggregation. Additionally, the low‐polarity microdomain of the carrier serves as a hydrophobic barrier, shielding protein drugs from water and preventing chemical degradation. Consequently, this work believes that the lecithin‐based reverse micelle system holds significant potential in providing new theoretical insights and experimental support for the advancement of pMDIs containing protein drugs.

Recent Update on Nanoemulsion Impregnated Hydrogel: a Gleam into the Revolutionary Strategy for Diffusion-Controlled Delivery of Therapeutics

Since earlier times, dermatological remedies have been utilized to treat diseases associated with pain, irritation, and skin conditions. Compared to other routes of drug delivery, topical delivery of drugs offers several benefits. Scientists are investigating different alterations in dosage forms in addition to existing topical formulations such as ointments, gels, creams, lotions, and ointments to significantly improve the permeation of drugs and enhance the pharmacological efficacy of medications that are poorly absorbed via the skin. Conventional formulations have a plethora of problems viz. poor absorption, no target specificity, low spreadability, and inadequate bioavailability which leads the researchers toward developing novel formulations like nanoemulsions. The nanoemulsion can enhance the gradient in concentration and thermodynamic movement toward the epidermis and enhance the penetration of its constituents. However, due to its difficult application, nanoemulsion's lower viscosity limited its use in transdermal delivery. Thus, the development of nanoemulsion-based hydrogels has shown to be a successful strategy for removing obstacles from existing drug formulations. The simple application, expedient spreadability, non-stickiness, safety, and effectiveness of nanoemulsion-based hydrogel have led to substantial growth in their research in recent years. This review gives a brief idea about the prevalence of skin diseases, skin as an obstacle for drug delivery, and recent research insights to combat these obstacles. The work highlights the mechanism of drug release via nanoemulsion, hydrogels, and nanoemulsion-based hydrogels with reference to recent research on hydrophobic and hydrophilic drugs.

Challenges and opportunities in delivering oral peptides and proteins

INTRODUCTION

Rapid advances in bioengineering enable the use of complex proteins as therapeutic agents to treat diseases. Compared with conventional small molecule drugs, proteins have multiple advantages, including high bioactivity and specificity with low toxicity. Developing oral dosage forms with active proteins is a route to improve patient compliance and significantly reduce production costs. However, the gastrointestinal environment remains a challenge to this delivery path due to enzymatic degradation, low permeability, and weak absorption, leading to reduced delivery efficiency and poor clinical outcomes.

AREAS COVERED

This review describes the barriers to oral delivery of peptides and complex proteins, current oral delivery strategies utilized and the opportunities and challenges ahead to try and circumvent these barriers. Oral protein drugs on the market and clinical trials provide insights and approaches for advancing delivery strategies.

EXPERT OPINION

Although most current studies on oral protein delivery rely on in vitro and in vivo animal data, the safety and limitations of the approach in humans remain uncertain. The shortage of clinical data limits the development of new or alternative strategies. Therefore, designing appropriate oral delivery strategies remains a significant challenge and requires new ideas, innovative design strategies and novel model systems.

Microneedle-Mediated Transdermal Delivery of Biopharmaceuticals

Transdermal delivery provides numerous benefits over conventional routes of administration. However, this strategy is generally limited to a few molecules with specific physicochemical properties (low molecular weight, high potency, and moderate lipophilicity) due to the barrier function of the stratum corneum layer. Researchers have developed several physical enhancement techniques to expand the applications of the transdermal field; among these, microneedle technology has recently emerged as a promising platform to deliver therapeutic agents of any size into and across the skin. Typically, hydrophilic biomolecules cannot penetrate the skin by passive diffusion. Microneedle insertion disrupts skin integrity and compromises its protective function, thus creating pathways (microchannels) for enhanced permeation of macromolecules. Microneedles not only improve stability but also enhance skin delivery of various biomolecules. Academic institutions and industrial companies have invested substantial resources in the development of microneedle systems for biopharmaceutical delivery. This review article summarizes the most recent research to provide a comprehensive discussion about microneedle-mediated delivery of macromolecules, covering various topics from the introduction of the skin, transdermal delivery, microneedles, and biopharmaceuticals (current status, conventional administration, and stability issues), to different microneedle types, clinical trials, safety and acceptability of microneedles, manufacturing and regulatory issues, and the future of microneedle technology.

Translational Nanomedicines Across Human Reproductive Organs Modeling on Microfluidic Chips: State-of-the-Art and Future Prospects

Forecasting the consequence of nanoparticles (NPs) and therapeutically significant molecules before materializing for human clinical trials is a mainstay for drug delivery and screening processes. One of the noteworthy obstacles that has prevented the clinical translation of NP-based drug delivery systems and novel drugs is the lack of effective preclinical platforms. As a revolutionary technology, the organ-on-a-chip (OOC), a coalition of microfluidics and tissue engineering, has surfaced as an alternative to orthodox screening platforms. OOC technology recapitulates the structural and physiological features of human organs along with intercommunications between tissues on a chip. The current review discusses the concept of microfluidics and confers cutting-edge fabrication processes for chip designing. We also outlined the advantages of microfluidics in analyzing NPs in terms of characterization, transport, and degradation in biological systems. The review further elaborates the scope and research on translational nanomedicines in human reproductive organs (testis, placenta, uterus, and menstrual cycle) by taking the advantages offered by microfluidics and shedding light on their potential future implications. Finally, we accentuate the existing challenges for clinical translation and scale-up dynamics for microfluidics chips and emphasize its future perspectives.

Molecular docking and simulation studies of synthetic protease inhibitors against COVID-19: a computational study

COVID-19 is the most recent threat to global health. Many people preferred treatment in case of infection instead of vaccination. The inhibition of viral replication is a good strategy for the treatment of COVID-19 infection. 3CLpro and PLpro are two important viral proteases responsible for proteolysis, infection, and replication of the virus. Therefore, targeting of these two enzymes is an attractive way to deal with COVID-19. The aim of this study was to screen some synthetic protease inhibitors to determine an appropriate hit molecule against COVID-19 using molecular docking and molecular dynamic simulations. The strategy depends on docking existing synthetic compounds mostly HIV protease inhibitors against two COVID-19 proteases to identify promising drugs for the treatment of COVID-19. We used protein data bank to obtain the X-ray crystal structure of the most important COVID-19 proteases 3CL pro (PDB ID: 6M2N) and PL pro (PDB ID: 6WX4). In this conceptual context, an attempt has been made to suggest an in silico computational relationship between 50 synthetic protease inhibitors and COVID-19 proteases. Out of 50 screened compounds, the best docking scores were found for these five protease inhibitors BDBM7021, BDBM698, BDBM694, BDBM93239, BDBM700. A 100-ns MD simulation was carried out to assess the stability of COVID-19 proteases and inhibitors, revealing an average RMSD value of 0.7 and favorable binding free energy (MM-GBSA) for all complexes confirming their potency as powerful binders in the COVID-19 proteases' binding pocket. Furthermore, the current results must be confirmed using in-vitro and in-vivo antiviral methods.Communicated by Ramaswamy H. Sarma.

Polymer nanotherapeutics: A versatile platform for effective rheumatoid arthritis therapy

Rheumatoid arthritis is an aggressive and severely debilitating disorder that is characterized by joint pain and cartilage damage. It restricts mobility in patients, leaving them unable to carry out simple tasks. RA presents itself with severe lasting pain, swelling and stiffness in the joints and may cause permanent disability in patients. Treatment regimens currently employed for rheumatoid arthritis revolve around keeping clinical symptoms like joint pain, inflammation, swelling and stiffness at bay. The current therapeutic interventions in rheumatoid arthritis involve the use of non-steroidal anti-inflammatory drugs, glucocorticoids, disease-modifying anti-rheumatic drugs and newer biological drugs that are engineered for inhibiting the expression of pro-inflammatory mediators. These conventional drugs are plagued with severe adverse effects because of their higher systemic distribution, lack of specificity and higher doses. Oral, intra-articular, and intravenous routes are routinely used for drug delivery which is associated with decreased patient compliance, high cost, poor bioavailability and rapid systemic clearance. All these drawbacks have enticed researchers to create novel strategies for drug delivery, the main approach being nanocarrier-based systems. In this article, we aim to consolidate the remarkable contributions of polymeric carrier systems including microneedle technology and smart trigger-responsive polymeric carriers in the management of rheumatoid arthritis along with its detailed pathophysiology. This review also briefly describes the safety and regulatory aspects of polymer therapeutics.

Potentials of Neuropeptides as Therapeutic Agents for Neurological Diseases

Despite recent leaps in modern medicine, progress in the treatment of neurological diseases remains slow. The near impermeable blood-brain barrier (BBB) that prevents the entry of therapeutics into the brain, and the complexity of neurological processes, limits the specificity of potential therapeutics. Moreover, a lack of etiological understanding and the irreversible nature of neurological conditions have resulted in low tolerability and high failure rates towards existing small molecule-based treatments. Neuropeptides, which are small proteinaceous molecules produced by the body, either in the nervous system or the peripheral organs, modulate neurological function. Although peptide-based therapeutics originated from the treatment of metabolic diseases in the 1920s, the adoption and development of peptide drugs for neurological conditions are relatively recent. In this review, we examine the natural roles of neuropeptides in the modulation of neurological function and the development of neurological disorders. Furthermore, we highlight the potential of these proteinaceous molecules in filling gaps in current therapeutics.

Pulmonary delivery of mucosal nanovaccines

Mucosal vaccination can elicit both systemic and mucosal immunity, and therefore has the potential to not only treat mucosal immune diseases, prevent the pathogen infection at the mucosal entry sites, but also treat distant or systemic immune disorders. However, only a few mucosal vaccines have been approved for human use in the clinic. Effective mucosal immunization requires the delivery of immunogenic agents to appropriate mucosal surfaces, which remains significantly challenging due to the essential biological barriers presenting at mucosal tissues. In the past decade, remarkable progress has been made in the development of pulmonary mucosal nanovaccines. The nanovaccines leverage advanced nanoparticle-based pulmonary delivery technologies on the characteristics of large surface area and rich antigen presentation cell environment of the lungs for triggering robust immune protection against various mucosal diseases. Herein, we review current methods and formulations of pulmonary delivery, discuss the design strategies of mucosal nanovaccines for potent and long-lasting immune responses, and highlight recent advances in the application of lipid-based pulmonary nanovaccines against mucosal diseases. These advances promise to accelerate the development of novel mucosal nanovaccines for the prophylaxis and therapy of infectious diseases, and cancer, as well as autoimmune disorders at mucosal tissues.

A Comprehensive Review of Therapeutic Approaches Available for the Treatment of Dermatitis

BACKGROUND

Dermatitis or eczema is a prevalent skin disorder worldwide and is also very common as a pediatric inflammatory skin disorder. Its succession gets worse with the multiple comorbidities which exhibit mechanisms that are poorly understood. Its management further becomes a challenge due to the limited effective treatment options available. However, the Novel Drug Delivery Systems (NDDS) along with new targeting strategies can easily bypass the issues associated with dermatitis management. If we compare the active constituents against phytoconstituents effective against dermatitis then phytoconstituents can be perceived to be more safe and gentle.

OBJECTIVE

Administration of NDDS of plant extract or actives displays improved absorption behavior, which helps them to permeate through lipid-rich biological membrane leading to increased bioavailability. The newer efficient discoveries related to eczema can face various exploitations. This can be intervened by the subjection of patent rights, which not only safeguard the novel works of individual(s) but also give them the opportunity to share details of their inventions with people globally.

CONCLUSION

The present review focuses on the available research about the use of nanoformulations in the topical delivery. It further elaborates the use of different animal models as the basis to characterize the different features of dermatitis. The review also highlights the recent nanoformulations which have the ability to amplify the delivery of active agents through their incorporation in transfersomes, ethosomes, niosomes or phytosomes, etc.

Magnetic solid-phase extraction of high molecular weight peptides using stearic acid-functionalized magnetic hydroxyapatite nanocomposite: determination of some hypothalamic agents in biological samples

Therapeutic peptides have an important effect on physiological function and human health, so it is momentous to quantify and detect low levels of these biomolecules in biological samples for treatment and diagnostic purposes. In the present study, an efficient magnetic solid-phase extraction (MSPE) method was developed based on stearic acid-functionalized magnetic hydroxyapatite nanocomposite (MHAP/SA) as a novel and cost-effective adsorbent for extraction of five hypothalamic-related peptides (goserelin, octreotide, triptorelin, somatostatin, and cetrorelix) from biological samples. To characterize the morphology and physicochemical properties of MHAP/SA, Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), field emission scanning microscopy (FE-SEM), CHNS elemental analysis, Brunauer-Emmett-Teller (BET), and vibrating sample magnetometry (VSM) were applied. Under optimum conditions, the proposed method (MSPE-HPLC-UV) represented favorable linearity with R² ≥ 0.9987, suitable intra- and inter-day precisions (RSD ≤ 6.9% and RSD ≤ 8.1%, respectively, n = 3), and limits of detection and quantification in the range of 0.75-1.12 ng mL^-1 and 2.50-3.75 ng mL^-1, respectively. Eventually, the proposed method was used for the extraction and quantification of target therapeutic peptides in plasma and urine samples, and satisfactory relative recoveries were achieved in the range of 90.6-110.3%.

Transdermal Co-Delivery of Urea and Recombinant Human Growth Hormone

BACKGROUND

Urea with super-hydrating and moisturizing properties is mainly used as an adjunctive treatment of diseases associated with dry skin. In this regard, the recombinant human growth hormone (rhGH) with rejuvenating properties is used as a base material in beauty creams. Although urea easily passes through the skin, the epidermal skin barrier restricts the passage of hGH due to its size.

OBJECTIVE

in this research, in order to solve this problem, hydroxy propyl-beta cyclodextrin (HP-β-CD) is used as a soluble chemical enhancer.

MATERIAL AND METHODS

UV and circular dichroism spectroscopy were used for the investigation of structural modification. The permeation process was studied in vitro on rat skin using vertical Franz diffusion cells. Enzyme-linked immunosorbent assay were used for rhGH activity assessment and evaluation of transdermal delivery.

RESULTS

First, due to the denaturing effects of urea on proteins its concentration was optimized to maintain biological structure and protein activity. UV spectroscopy and CD data proved that the secondary structure of rhGH is preserved in the presence of urea (0.5-2 M) and HP-β-CD, which elevates urea and rhGH permeation. Maximum permeability was observed at 120 min after sampling (1424.35 ng.ml.cm^-2), which was much higher than the control. Using a higher concentration of urea in the formulation will significantly decrease the level of rhGH delivery.

CONCLUSION

According to results, this strategy can be considered as a successful method for enhanced Co-delivery of rhGH and urea.

Affinity-Controlled Double-Network Hydrogel Facilitates Long-Term Release of Anti-Human Papillomavirus Protein

Hydrogels have recently received attention as delivery carriers owing to their good biocompatibility and structural similarity to natural extracellular matrices. However, the utilization of traditional single-network (SN) hydrogels is limited by poor mechanical properties and burst drug release. Therefore, we developed a novel double-network (DN) hydrogel, which employs an alginate (ALG)/polyethylene glycol diacrylate (PEGDA) network to adjust the mechanical strength and a positively charged monomer AETAC (2-(acryloyloxy)ethyl]trimethyl-ammonium chloride) to regulate the release curve of the electronegative anti-human papillomavirus (HPV) protein (bovine β-lactoglobulin modified with 3-hydroxyphthalic anhydride) based on an affinity-controlled delivery mechanism. The results show that the double-network hydrogel strongly inhibits the burst release, and the burst release amount is about one-third of that of the single-network hydrogel. By changing the concentration of the photoinitiator, the mechanical strength of the DN hydrogels can be adjusted to meet the stiffness requirements for various tissues within the range of 0.71 kPa to 10.30 kPa. Compared with the SN hydrogels, the DN hydrogels exhibit almost twice the mechanical strength and have smaller micropores. Cytotoxicity tests indicated that these SN and DN hydrogels were not cytotoxic with the result of over 100% relative proliferation rate of the HUVECs. Furthermore, DN hydrogels can significantly alleviate the burst release of antiviral proteins and prolong the release time to more than 14 days. Finally, we utilized digital light processing (DLP) technology to verify the printability of the DN hydrogel. Our study indicates that ALG/PEGDA-AETAC DN hydrogels could serve as platforms for delivering proteins and show promise for diverse tissue engineering applications.

PLGA-based biodegradable microspheres in drug delivery: recent advances in research and application

Biodegradable microspheres have been widely used in the field of medicine due to their ability to deliver drug molecules of various properties through multiple pathways and their advantages of low dose and low side effects. Poly (lactic-co-glycolic acid) copolymer (PLGA) is one of the most widely used biodegradable material currently and has good biocompatibility. In application, PLGA with a specific monomer ratio (lactic acid and glycolic acid) can be selected according to the properties of drug molecules and the requirements of the drug release rate. PLGA-based biodegradable microspheres have been studied in the field of drug delivery, including the delivery of various anticancer drugs, protein or peptide drugs, bacterial or viral DNA, etc. This review describes the basic knowledge and current situation of PLGA biodegradable microspheres and discusses the selection of PLGA polymer materials. Then, the preparation methods of PLGA microspheres are introduced, including emulsification, microfluidic technology, electrospray, and spray drying. Finally, this review summarizes the application of PLGA microspheres in drug delivery and the treatment of pulmonary and ocular-related diseases.

Skin Barriers in Dermal Drug Delivery: Which Barriers Have to Be Overcome and How Can We Measure Them?

Although, drugs are required in the various skin compartments such as viable epidermis, dermis, or hair follicles, to efficiently treat skin diseases, drug delivery into and across the skin is still challenging. An improved understanding of skin barrier physiology is mandatory to optimize drug penetration and permeation. The various barriers of the skin have to be known in detail, which means methods are needed to measure their functionality and outside-in or inside-out passage of molecules through the various barriers. In this review, we summarize our current knowledge about mechanical barriers, i.e., stratum corneum and tight junctions, in interfollicular epidermis, hair follicles and glands. Furthermore, we discuss the barrier properties of the basement membrane and dermal blood vessels. Barrier alterations found in skin of patients with atopic dermatitis are described. Finally, we critically compare the up-to-date applicability of several physical, biochemical and microscopic methods such as transepidermal water loss, impedance spectroscopy, Raman spectroscopy, immunohistochemical stainings, optical coherence microscopy and multiphoton microscopy to distinctly address the different barriers and to measure permeation through these barriers in vitro and in vivo.