Bioresorbable pH- and temperature-responsive injectable hydrogels-incorporating electrosprayed particles for the sustained release of insulin

Preparation and characterization of the injectable pH- and temperature-sensitive pentablock hydrogel containing human growth hormone-loaded chitosan nanoparticles via electrospraying

This research investigated the in vivo gelation, biodegradation, and drug release efficiency of a novel injectable sensitive drug delivery system for human growth hormone (HGh). This composite system comprises pH- and temperature-sensitive hydrogel, designated as oligomer serine-b-poly(lactide)-b-poly(ethylene glycol)-b-poly(lactide)-b-oligomer serine (OS-PLA-PEG-PLA-OS) pentablock copolymer, as matrix and electrosprayed HGh-loaded chitosan (HGh@CS) nanoparticles (NPs) as principal material. The proton nuclear magnetic resonance spectrum of the pH- and temperature-sensitive OS-PLA-PEG-PLA-OS pentablock copolymer hydrogel proved that this copolymer was successfully synthesized. The HGh was encapsulated in chitosan (CS) NPs by an electrospraying system in acetic acid with appropriate granulation parameters. The scanning electron microscopy images and size distribution showed that the HGh@CS NPs formed had an average diameter of 366.1 ± 214.5 nm with a discrete spherical shape and dispersed morphology. The sol-gel transition of complex gel based on HGh@CS NPs and OS-PLA-PEG-PLA-OS pentablock hydrogel was investigated at 15 °C and pH 7.8 in the sol state and gelled at 37 °C and pH 7.4, which is suitable for the physiological conditions of the human body. The HGh release experiment of the composite system was performed in an in vivo environment, which demonstrated the ability to release HGh, and underwent biodegradation within 32 days. The findings of the investigation revealed that the distribution of HGh@CS NPs into the hydrogel matrix not only improved the mechanical properties of the gel matrix but also controlled the drug release kinetics into the systematic bloodstream, which ultimately promotes the desired therapeutic body growth depending on the distinct concentration used.

Orally ingestible medication utilizing layered double hydroxide nanoparticles strengthened alginate and hyaluronic acid-based hydrogel bead for bowel disease management

In the treatment of bowel diseases such as ulcerative colitis through oral administration, an effective drug delivery system targeting the colon is crucial for enhancing efficacy and minimizing side effects of therapeutic agents. This study focuses on the development of a novel nanocomposite hydrogel bead comprising a synergistic blend of biological macromolecules, namely sodium alginate (ALG) and hyaluronic acid (HA), reinforced with layered double hydroxide nanoparticles (LDHs) for the oral delivery of dual therapeutics. The synthesized hydrogel bead exhibits significantly enhanced gel strength and controllable release of methylprednisolone (MP) and curcumin (CUR), serving as an anti-inflammatory drug and a mucosal healing agent, compared to native ALG or ALG/HA hydrogel beads without LDHs. The physicochemical properties of the synthesized LDHs and hydrogel beads were characterized using various techniques, including scanning electron microscopy, zeta potential measurement, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. In vitro release studies of MP and CUR under simulated gastrointestinal tract (GIT) conditions demonstrate the superior controlled release property of the nanocomposite hydrogel bead, particularly in minimizing premature drug release in the upper GIT environment while sustaining release of over 82 % of drugs in the colonic environment. Thus, the modularly engineered carrier designed for oral colon targeting holds promise as a potential candidate for the treatment of ulcerative colitis.

Reasoning on Pore Terminology in 3D Bioprinting

Terminology is pivotal for facilitating clear communication and minimizing ambiguity, especially in specialized fields such as chemistry. In materials science, a subset of chemistry, the term "pore" is traditionally linked to the International Union of Pure and Applied Chemistry (IUPAC) nomenclature, which categorizes pores into "micro", "meso", and "macro" based on size. However, applying this terminology in closely-related areas, such as 3D bioprinting, often leads to confusion owing to the lack of consensus on specific definitions and classifications tailored to each field. This review article critically examines the current use of pore terminology in the context of 3D bioprinting, highlighting the need for reassessment to avoid potential misunderstandings. We propose an alternative classification that aligns more closely with the specific requirements of bioprinting, suggesting a tentative size-based division of interconnected pores into 'parvo'-(d < 25 µm), 'medio'-(25 < d < 100 µm), and 'magno'-(d > 100 µm) pores, relying on the current understanding of the pore size role in tissue formation. The introduction of field-specific terminology for pore sizes in 3D bioprinting is essential to enhance the clarity and precision of research communication. This represents a step toward a more cohesive and specialized lexicon that aligns with the unique aspects of bioprinting and tissue engineering.

Non-Invasive Delivery of Insulin for Breaching Hindrances against Diabetes

Insulin is recognized as a crucial weapon in managing diabetes. Subcutaneous (s.c.) injections are the traditional approach for insulin administration, which usually have many limitations. Numerous alternative (non-invasive) slants through different routes have been explored by the researchers for making needle-free delivery of insulin for attaining its augmented absorption as well as bioavailability. The current review delineating numerous pros and cons of several novel approaches of non-invasive insulin delivery by overcoming many of their hurdles. Primary information on the topic was gathered by searching scholarly articles from PubMed added with extraction of data from auxiliary manuscripts. Many approaches (discussed in the article) are meant for the delivery of a safe, effective, stable, and patient friendly administration of insulin via buccal, oral, inhalational, transdermal, intranasal, ocular, vaginal and rectal routes. Few of them have proven their clinical efficacy for maintaining the glycemic levels, whereas others are under the investigational pipe line. The developed products are comprising of many advanced micro/nano composite technologies and few of them might be entering into the market in near future, thereby garnishing the hopes of millions of diabetics who are under the network of s.c. insulin injections.

Chitosan-Based Particulate Carriers: Structure, Production and Corresponding Controlled Release

The state of the art in the use of chitosan (CS) for preparing particulate carriers for drug delivery applications is reviewed. After evidencing the scientific and commercial potentials of CS, the links between targeted controlled activity, the preparation process and the kinetics of release are detailed, focusing on two types of particulate carriers: matrix particles and capsules. More precisely, the relationship between the size/structure of CS-based particles as multifunctional delivery systems and drug release kinetics (models) is emphasized. The preparation method and conditions greatly influence particle structure and size, which affect release properties. Various techniques available for characterizing particle structural properties and size distribution are reviewed. CS particulate carriers with different structures can achieve various release patterns, including zero-order, multi-pulsed, and pulse-triggered. Mathematical models have an unavoidable role in understanding release mechanisms and their interrelationships. Moreover, models help identify the key structural characteristics, thus saving experimental time. Furthermore, by investigating the close relation between preparation process parameters and particulate structural characteristics as well as their effect on release properties, a novel "on-demand" strategy for the design of drug delivery devices may be developed. This reverse strategy involves designing the production process and the related particles' structure based on the targeted release pattern.

Injectable hydrogel imbibed with camptothecin-loaded mesoporous silica nanoparticles as an implantable sustained delivery depot for cancer therapy

In recent years, injectable stimuli-sensitive hydrogels are employed as suitable drug delivery carriers for the release of various anti-cancer drugs. However, large pore size of the microporous hydrogel trigger release of small molecular anticancer drug that limits hydrogel application in cancer therapy. Therefore, introducing reinforcing fillers such as mesoporous silica nanoparticles (MSNs) can not only load different type of anticancer drugs but also prevent the premature release of drugs due to the strengthening of the networks. Furthermore, high specific surface area, suitable size, large pore volume, and stable physicochemical properties of MSNs can improve the therapeutic efficacy. In this study, to sustain the release of hydrophobic anticancer drug, camptothecin (CPT) was loaded into MSNs, and then imbibed into the physiological stimuli-sensitive poly(ethylene glycol)-poly(β-aminoester urethane) (PAEU) hydrogels. MSN-imbibed PAEU hydrogels exhibited prolonged release of CPT than MSNs and PAEU hydrogel alone. Furthermore, MSN-imbibed PAEU copolymers form stable viscoelastic gel depot into the subcutaneous layers of Sprague-Dawley rats and found to be safe and not induced toxicity to healthy organs, implying biodegradability and safety of the hydrogels. Interestingly, CPT-loaded hydrogels shown dose-dependent toxicity to A549 and B16F10 cells. These results demonstrated that MSN-imbibed PAEU hydrogel with biocompatible, biodegradable, and in situ gel forming property could be a useful drug delivery depot for sustained release of anticancer drugs.

Smart stimuli-responsive chitosan hydrogel for drug delivery: A review

Smart stimuli-responsive materials can respond to different signals (pH, temperature, light, electricity, etc.), and they have become a hot research topic for drug delivery. As a polysaccharide polymer with excellent biocompatibility, chitosan can be obtained from diverse natural sources. Chitosan hydrogels with different stimuli-response capabilities are widely applied in the drug delivery field. This review highlights and discusses the research progress on chitosan hydrogels concerning their stimuli-responsive capabilities. The feature of various stimuli-responsive kinds of hydrogels is outlined, and their potential use of drug delivery is summarized. Furthermore, the questions and future development chances of stimuli-responsive chitosan hydrogels are analyzed by comparing the current published literature, and the directions for the intelligent development of chitosan hydrogels are discussed.

Synthesis and characterization of dual light/temperature-responsive supramolecular injectable hydrogel based on host-guest interaction between azobenzene and starch-grafted β-cyclodextrin: Melanoma therapy with paclitaxel

Injectable stimuli-responsive hydrogels could offer an opportunity for local administration at the tumor site and a sustained drug release. In this paper, a copolymer of azobenzene derivative and N-isopropyl acrylamide (NIPAM) was synthesized, which are performed as light- and thermo-sensitive parts, respectively. The DAS@SCD/NIPAZO hydrogel was prepared upon the establishment of host-guest interactions between the hydrophobic core of CD and azobenzene moiety. The LCST of the synthesized copolymer was modified from 31.3 °C to 36.5 °C by the incorporation of the hydrophilic host moieties of the modified starch into the NIPAM copolymer structure. The LCST-based property of the hydrogel made it syringable in low temperatures and switch to a gel state after local injection. The drug release profile of the hydrogel was explored in four different conditions involving two distinct temperatures combined with two different light wavelengths to examine the light- and thermo-sensitivity of the hydrogel. Moreover, a Paclitaxel-loaded hydrogel was prepared to study the in vitro efficiency of the sample and was investigated by MTT assay against the cancerous fibroblastic cells (A-431), which revealed a sharp decline in cell viability under 365 nm light irradiation; furthermore, to evaluate the in vivo effects of the PTX-loaded hydrogel, histological studies based on staining techniques were carried out.

Smart stimuli-responsive injectable gels and hydrogels for drug delivery and tissue engineering applications: A review

Hydrogels are widely used biomaterials in the delivery of therapeutic agents, including drugs, genes, proteins, etc., as well as tissue engineering, due to obvious properties such as biocompatibility and their similarity to natural body tissues. Some of these substances have the feature of injectability, which means that the substance is injected into the desired place in the solution state and then turns into the gel, which makes it possible to administer them from a way with a minimal amount of invasion and eliminate the need for surgery to implant pre-formed materials. Gelation can be caused by a stimulus and/or spontaneously. Suppose this induces due to the effect of one or many stimuli. In that case, the material in question is called stimuli-responsive because it responds to the surrounding conditions. In this context, we introduce the different stimuli that cause gelation and investigate the different mechanisms of the transformation of the solution into the gel in them. Also, we study special structures, such as nano gels or nanocomposite gels.

Ionically cross-linked alginate-chitosan core-shell hydrogel beads for oral delivery of insulin

Here, core-shell hydrogel beads for oral insulin delivery at intestine was reported, which was a target site for insulin absorption. The core-shell hydrogel beads were prepared using naturally derived alginate and chitosan polysaccharides by simple dropping technique. In order to effectively control leakage of insulin from core-shell hydrogel beads, insulin was embedded into the layered double hydroxides (LDHs). LDH/insulin-loaded complexes were firstly coated with chitosan, and then coated with alginate to generate core-shell hydrogel beads. The biocompatibility and angiogenic response of core-shell hydrogel beads were evaluated by direct contact of the beads with chick embryo chorioallantoic membrane, which indicates safety of the core-shell beads. The beads successfully retained the insulin within the core-shell structure at pH 1.2, indicating that insulin had a good protective effect in harsh acidic environments. Interestingly, insulin release starts at the simulated intestinal fluid (pH 6.8) and continue to release for 24 h in a sustained manner.

Gene Regulations upon Hydrogel-Mediated Drug Delivery Systems in Skin Cancers-An Overview

The incidence of skin cancer has increased dramatically in recent years, particularly in Caucasian populations. Specifically, the metastatic melanoma is one of the most aggressive cancers and is responsible for more than 80% of skin cancer deaths around the globe. Though there are many treatment techniques, and drugs have been used to cure this belligerent skin cancer, the side effects and reduced bioavailability of drug in the targeted area makes it difficult to eradicate. In addition, cellular metabolic pathways are controlled by the skin cancer driver genes, and mutations in these genes promote tumor progression. Consequently, the MAPK (RAS-RAF-MEK-ERK pathway), WNT and PI3K signaling pathways are found to be important molecular regulators in melanoma development. Even though hydrogels have turned out to be a promising drug delivery system in skin cancer treatment, the regulations at the molecular level have not been reported. Thus, we aimed to decipher the molecular pathways of hydrogel drug delivery systems for skin cancer in this review. Special attention has been paid to the hydrogel systems that deliver drugs to regulate MAPK, PI3K-AKT-mTOR, JAK-STAT and cGAS-STING pathways. These signaling pathways can be molecular drivers of skin cancers and possible potential targets for the further research on treatment of skin cancers.

Injectable Hydrogel Based on Protein-Polyester Microporous Network as an Implantable Niche for Active Cell Recruitment

Despite the potential of hydrogel-based localized cancer therapies, their efficacy can be limited by cancer recurrence. Therefore, it is of great significance to develop a hydrogel system that can provoke robust and durable immune response in the human body. This study has developed an injectable protein-polymer-based porous hydrogel network composed of lysozyme and poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide (PCLA) (Lys-PCLA) bioconjugate for the active recruitment dendritic cells (DCs). The Lys-PCLA bioconjugates are prepared using thiol-ene reaction between thiolated lysozyme (Lys-SH) and acrylated PCLA (PCLA-Ac). The free-flowing Lys-PCLA bioconjugate sols at low temperature transformed to immovable gel at the physiological condition and exhibited stability upon dilution with buffers. According to the in vitro toxicity test, the Lys-PCLA bioconjugate and PCLA copolymer were non-toxic to RAW 263.7 cells at higher concentrations (1000 µg/mL). In addition, subcutaneous administration of Lys-PCLA bioconjugate sols formed stable hydrogel depot instantly, which suggested the in situ gel forming ability of the bioconjugate. Moreover, the Lys-PCLA bioconjugate hydrogel depot formed at the interface between subcutaneous tissue and dermis layers allowed the active migration and recruitment of DCs. As suggested by these results, the in-situ forming injectable Lys-PCLA bioconjugate hydrogel depot may serve as an implantable immune niche for the recruitment and modification of DCs.

PCL-PEG copolymer based injectable thermosensitive hydrogels

A number of stimuli-responsive-based hydrogels has been widely explored in biomedical applications in the last few decades because of their excellent biodegradability and biocompatibility. The development of synthetic chemistry and materials science leads to the emergence of in situ stimuli-responsive hydrogels. In this regard, several synthetic and natural polymers have been synthesized and utilized to prepare temperature-sensitive in situ forming hydrogels. This could be best used via injections as temperature stimulus could trigger in situ hydrogels gelation and swelling behaviors. There are many smart polymers available for the formulation of the in situ based thermoresponsive injectable hydrogel. Among these, poly (ε-caprolactone) (PCL) polymer has been recognized and approved by the FDA for numerous biomedical applications. More specifically, the PCL is coupled with polyethylene glycol (PEG) to obtain amphiphilic thermosensitive "smart" copolymers (PCL-PEG), to form rapid and reversible physical gelation behavior. However, the chemical structure of the copolymer is a critical aspect in determining water solubility, thermo-gelation behavior, drug release rate, degradation rate, and the possibility to deliver a diverse range of drugs. In this review, we have highlighted the typical PCL-PEG-based thermosensitive injectable hydrogels progress in the last decade for tissue engineering and localized drug delivery applications to treat various diseases. Additionally, the impact of molecular weight of PCL-PEG upon gelling behavior has also been critically highlighted for optimum hydrogels properties for potential pharmaceutical and biomedical applications.

Recent progress in polymeric non-invasive insulin delivery

The design of carriers for insulin delivery has recently attracted major research attentions in the biomedical field. In general, the release of drug from polymers is driven via a variety of polymers. Several mechanisms such as matrix release, leaching of drug, swelling, and diffusion are usually adopted for the release of drug through polymers. Insulin is one of the most predominant therapeutic drugs for the treatment of both diabetes mellitus; type-I (insulin-dependent) and type II (insulin-independent). Currently, insulin is administered subcutaneously, which makes the patient feel discomfort, pain, hyperinsulinemia, allergic responses, lipodystrophy surrounding the injection area, and occurrence of miscarried glycemic control. Therefore, significant research interest has been focused on designing and developing new insulin delivery technologies to control blood glucose levels and time, which can enhance the patient compliance simultaneously through alternative routes as non-invasive insulin delivery. The aim of this review is to emphasize various non-invasive insulin delivery mechanisms including oral, transdermal, rectal, vaginal, ocular, and nasal. In addition, this review highlights different smart stimuli-responsive insulin delivery systems including glucose, pH, enzymes, near-infrared, ultrasound, magnetic and electric fields, and the application of various polymers as insulin carriers. Finally, the advantages, limitations, and the effect of each non-invasive route on insulin delivery are discussed in detail.

Degradation-triggered release from biodegradable metallic surfaces

This work is dedicated to the investigation of drug-release control by a direct effect of degradation from biodegradable metallic surfaces. Degradation behaviors characterized by surface morphology, immersion, and electrochemical techniques demonstrated that curcumin-coated zinc (c-Zn) had a higher degradation rate compared to curcumin-coated Fe (c-Fe). High anodic dissolution rate due to the higher degradation rate and widely extended groove-like degradation structure of c-Zn propelled a higher curcumin release. On the other hand, a slower curcumin release rate shown by c-Fe scaffolds is ascribed to its lower anodic dissolution and to its pitting degradation regime with relatively smaller pits. These findings illuminate the remarkable advantage of different degradation behaviors of degradable metallic surfaces in directly controlling the drug release without the need for external electrical stimulus.

Emerging Role of Hydrogels in Drug Delivery Systems, Tissue Engineering and Wound Management

The popularity of hydrogels as biomaterials lies in their tunable physical properties, ability to encapsulate small molecules and macromolecular drugs, water holding capacity, flexibility, and controllable degradability. Functionalization strategies to overcome the deficiencies of conventional hydrogels and expand the role of advanced hydrogels such as DNA hydrogels are extensively discussed in this review. Different types of cross-linking techniques, materials utilized, procedures, advantages, and disadvantages covering hydrogels are tabulated. The application of hydrogels, particularly in buccal, oral, vaginal, and transdermal drug delivery systems, are described. The review also focuses on composite hydrogels with enhanced properties that are being developed to meet the diverse demand of wound dressing materials. The unique advantages of hydrogel nanoparticles in targeted and intracellular delivery of various therapeutic agents are explained. Furthermore, different types of hydrogel-based materials utilized for tissue engineering applications and fabrication of contact lens are discussed. The article also provides an overview of selected examples of commercial products launched particularly in the area of oral and ocular drug delivery systems and wound dressing materials. Hydrogels can be prepared with a wide variety of properties, achieving biostable, bioresorbable, and biodegradable polymer matrices, whose mechanical properties and degree of swelling are tailored with a specific application. These unique features give them a promising future in the fields of drug delivery systems and applied biomedicine.

Advances in biodegradable and injectable hydrogels for biomedical applications

In situ-forming injectable hydrogels are smart biomaterials that can be implanted into living bodies with minimal invasion. Due to pioneer work of Prof. Sung Wan Kim in this field, injectable hydrogels have shown great potentials in many different biomedical applications. Biodegradable and injectable hydrogels can be administered at room temperature as viscous polymer sols. They will degrade after accomplishing their tasks. Before injecting into living bodies, active substances can be loaded into viscous polymer sols with a high loading efficiency by simple mixing. After injecting into living bodies, active substances-loaded hydrogels can be formed and active substances can be released in a controlled manner upon diffusion or polymer degradation. Due to their outstanding properties and unique features, injectable hydrogels are very promising in many biomedical applications including drug/protein/gene delivery, tissue engineering, and regenerative medicine. In this review, we briefly introduce recent development of several important types of in situ-forming injectable hydrogels reported by our group during the last three years. Important properties and potential applications (such as cancer therapy, insulin release and wound healing) of these injectable hydrogels are reviewed. Challenges and perspectives in this research field are also discussed.

Embedding Ordered Mesoporous Carbons into Thermosensitive Hydrogels: A Cutting-Edge Strategy to Vehiculate a Cargo and Control Its Release Profile

The high drug loading capacity, cytocompatibility and easy functionalization of ordered mesoporous carbons (OMCs) make them attractive nanocarriers to treat several pathologies. OMCs’ efficiency could be further increased by embedding them into a hydrogel phase for an in loco prolonged drug release. In this work, OMCs were embedded into injectable thermosensitive hydrogels. In detail, rod-like (diameter ca. 250 nm, length ca. 700 nm) and spherical (diameter approximately 120 nm) OMCs were synthesized by nanocasting selected templates and loaded with ibuprofen through a melt infiltration method to achieve complete filling of their pores (100% loading yield). In parallel, an amphiphilic Poloxamer^® 407-based poly(ether urethane) was synthesized (Mn¯ 72 kDa) and solubilized at 15 and 20% w/v concentration in saline solution to design thermosensitive hydrogels. OMC incorporation into the hydrogels (10 mg/mL concentration) did not negatively affect their gelation potential. Hybrid systems successfully released ibuprofen at a slower rate compared to control gels (gels embedding ibuprofen as such), but with no significant differences between rod-like and spherical OMC-loaded gels. OMCs can thus work as effective drug reservoirs that progressively release their payload over time and also upon encapsulation in a hydrogel phase, thus opening the way to their application to treat many different pathological states (e.g., as topical medications).

Cutting-edge progress and challenges in stimuli responsive hydrogel microenvironment for success in tissue engineering today

The field of tissue engineering has numerous potential for modified therapeutic results and has been inspired by enhancements in bioengineering at the recent decades. The techniques of regenerating tissues and assembling functional paradigms that are responsible for repairing, maintaining, and revitalizing lost organs and tissues have affected the entire spectrum of health care studies. Strategies to combine bioactive molecules, biocompatible materials and cells are important for progressing the renewal of damaged tissues. Hydrogels have been utilized as one of the most popular cell substrate/carrier in tissue engineering since previous decades, respect to their potential to retain a 3D structure, to protect the embedded cells, and to mimic the native ECM. The hydrophilic nature of hydrogels can provide an ideal milieu for cell viability and structure, which simulate the native tissues. Hydrogel systems have been applied as a favorable matrix for growth factor delivery and cell immobilization. This study reviews a brief explanation of the structure, characters, applications, fabrication methods, and future outlooks of stimuli responsive hydrogels in tissue engineering and, in particular, 3D bioprinting.

A novel injectable pH-temperature sensitive hydrogel containing chitosan-insulin electrosprayed nanosphere composite for an insulin delivery system in type I diabetes treatment

A novel insulin composite delivery system was prepared and characterized. The composite consisted of a pH- and temperature-sensitive hydrogel, which is an oligomer serine-b-poly(lactide)-b-poly(ethylene glycol)-b-poly(lactide)-b-oligomer serine (OS-PLA-PEG-PLA-OS) pentablock copolymer, as matrix and chitosan-insulin electrosprayed nanospheres (CIN) as constituent materials. The properties of the OS-PLA-PEG-PLA-OS pentablock copolymer and the chitosan-insulin nanoparticles were characterized. The chitosan-insulin nanospheres uniformly distributed in the matrix had a reinforcing effect on the mechanical properties and prolonged the degradation time of the hydrogel depot under body conditions. The composite solutions accommodating different concentrations of the chitosan-insulin nanospheres were subcutaneously injected into induced diabetic BALB/c mice to study the in vivo insulin-release profile. The result showed that insulin concentrations in blood plasma were maintained at a steady-state level. Furthermore, the bio-properties of the insulin were retained and it showed a blood glucose level reducing effect for more than 60 hours after injection to a streptozotocin (STZ)-induced diabetic mouse model. The results suggested that this injectable pH-temperature sensitive hydrogel containing chitosan-insulin electrosprayed nanosphere composites has promising potential applications for type 1 diabetes treatment.

Rational Design and Synthesis of Diverse Pyrimidine Molecules Bearing Sulfonamide Moiety as Novel ERK Inhibitors

Protein kinases orchestrate diverse cellular functions; however, their dysregulation is linked to metabolic dysfunctions, associated with many diseases, including cancer. Mitogen-Activated Protein (MAP) kinase is a notoriously oncogenic signaling pathway in human malignancies, where the extracellular signal-regulated kinases (ERK1/2) are focal serine/threonine kinases in the MAP kinase module with numerous cytosolic and nuclear mitogenic effector proteins. Subsequently, hampering the ERK kinase activity by small molecule inhibitors is a robust strategy to control the malignancies with aberrant MAP kinase signaling cascades. Consequently, new heterocyclic compounds, containing a sulfonamide moiety, were rationally designed, aided by the molecular docking of the starting reactant 1-(4-((4-methylpiperidin-1-yl)sulfonyl)phenyl)ethan-1-one (3) at the ATP binding pocket of the ERK kinase domain, which was relying on the molecular extension tactic. The identities of the synthesized compounds (4–33) were proven by their spectral data and elemental analysis. The target compounds exhibited pronounced anti-proliferative activities against the MCF-7, HepG-2, and HCT-116 cancerous cell lines with potencies reaching a 2.96 μM for the most active compound (22). Moreover, compounds 5, 9, 10b, 22, and 28 displayed a significant G2/M phase arrest and induction of the apoptosis, which was confirmed by the cell cycle analysis and the flow cytometry. Thus, the molecular extension of a small fragment bounded at the ERK kinase domain is a valid tactic for the rational synthesis of the ERK inhibitors to control various human malignancies.

Thermo-sensitive hydrogels for delivering biotherapeutic molecules: A review

To date, a variety of delivery systems based on organic or inorganic materials have been investigated. Among them, hydrogels have become one of the most promising field in drug delivery system due to their unique properties. Temperature-sensitive hydrogels, which gelation at physiological temperature, gift the delivery system with excellent spatial and temporal control, and have a widely application in drug delivery, tissue engineering, imaging, and wound dressing. This review provides a brief overview on the concept and classification of temperature-sensitive hydrogels, and covers the application of temperature-sensitive gel systems in delivery of biotherapeutic molecules.