The Stability Maintenance of Protein Drugs in Organic Coatings Based on Nanogels

Rational Design and Development of Polymeric Nanogels as Protein Carriers

Proteins have gained significant attention as potential therapeutic agents owing to their high specificity and reduced toxicity. Nevertheless, their clinical utility is hindered by inherent challenges associated with stability during storage and after in vivo administration. To overcome these limitations, polymeric nanogels (NGs) have emerged as promising carriers. These colloidal systems are capable of efficient encapsulation and stabilization of protein cargoes while improving their bioavailability and targeted delivery. The design of such delivery systems requires a comprehensive understanding of how the synthesis and formulation processes affect the final performance of the protein. This review highlights critical aspects involved in the development of NGs for protein delivery, with specific emphasis on loading strategies and evaluation techniques. For example, factors influencing loading efficiency and release kinetics are discussed, along with strategies to optimize protein encapsulation through protein-carrier interactions to achieve the desired therapeutic outcomes. The discussion is based on recent literature examples and aims to provide valuable insights for researchers working toward the advancement of protein-based therapeutics.

Microfluidic manufacturing of tioconazole loaded keratin nanocarriers: Development and optimization by design of experiments

Fungal infections of the skin, nails, and hair are a common health concern affecting a significant proportion of the population worldwide. The current treatment options include topical and systematic agents which have low permeability and prolonged treatment period, respectively. Consequently, there is a growing need for a permeable, effective, and safe treatment. Keratin nanoparticles are a promising nanoformulation that can improve antifungal agent penetration, providing sustainable targeted drug delivery. In this study, keratin nanoparticles were prepared using a custom-made 3D-printed microfluidic chip and the manufacturing process was optimized using the design of experiments (DoE) approach. The total flow rate (TFR), flow rate ratio (FRR), and keratin concentration were found to be the most influential factors of the size and polydispersity index (PDI) of the nanoparticles. The crosslinking procedure by means of tannic acid as safe and biocompatible compound was also optimized. Keratin nanoparticles loaded with a different amount of tioconazole showed a size lower than 200 nm, a PDI lower than 0.2 and an encapsulation efficiency of 91 ± 1.9 %. Due to their sustained drug release, the formulations showed acceptable in vitro biocompatibility. Furthermore, a significant inhibitory effect compared to the free drug against Microsporum canis.

Biodegradable Nanogels for Dermal Applications: An Insight

Abstract:

Biodegradable nanogels in the biomedical field are emerging vehicles comprising dispersions of hydrogel nanoparticles having 3D crosslinked polymeric networks. Nanogels show distinguished characteristics including their homogeneity, adjustable size, low toxicity, stability in serum, stimuli-responsiveness (pH, temperature, enzymes, light, etc.), and relatively good drug encapsulation capability. Due to these characteristics, nanogels are referred to as nextgeneration drug delivery systems and are suggested as promising carriers for dermal applications. The site-specific delivery of drugs with effective therapeutic effects is crucial in transdermal drug delivery. The nanogels made from biodegradable polymers can show external stimuliresponsiveness which results in a change in gel volume, water content, colloidal stability, mechanical strength, and other physical and chemical properties, thus improving the site-specific topical drug delivery. This review provides insight into the advances in development, limitations, and therapeutic significance of nanogels formulations. It also highlights the process of release of drugs in response to external stimuli, various biodegradable polymers in the formulation of the nanogels, and dermal applications of nanogels and their role in imaging, anti‐inflammatory therapy, antifungal and antimicrobial therapy, anti‐psoriatic therapy, and ocular and protein/peptide drug delivery.

Recent advances of the nanocomposite hydrogel as a local drug delivery for diabetic ulcers

Diabetic ulcer is a serious complication of diabetes. Compared with that of healthy people, the skin of patients with a diabetic ulcer is more easily damaged and difficult to heal. Without early intervention, the disease will become increasingly serious, often leading to amputation or even death. Most current treatment methods cannot achieve a good wound healing effect. Numerous studies have shown that a nanocomposite hydrogel serves as an ideal drug delivery method to promote the healing of a diabetic ulcer because of its better drug loading capacity and stability. Nanocomposite hydrogels can be loaded with one or more drugs for application to chronic ulcer wounds to promote rapid wound healing. Therefore, this paper reviews the latest progress of delivery systems based on nanocomposite hydrogels in promoting diabetic ulcer healing. Through a review of the recent literature, we put forward the shortcomings and improvement strategies of nanocomposite hydrogels in the treatment of diabetic ulcers.

Metal organic framework-based antibacterial agents and their underlying mechanisms

Bacteria, as the most abundant living organisms, have always been a threat to human life until the development of antibiotics. However, with the wide use of antibiotics over a long time, bacteria have gradually gained tolerance to antibiotics, further aggravating threat to human beings and environmental safety significantly. In recent decades, new bacteria-killing methods based on metal ions, hyperthermia, free radicals, physical pricks, and the coordination of several multi-mechanisms have attracted increasing attention. Consequently, multiple types of new antibacterial agents have been developed. Among them, metal organic frameworks (MOFs) appear to play an increasingly important role. The unique characteristics of MOFs make them suitable multiple-functional platforms. By selecting the appropriate metastable coordination bonds, MOFs can act as reservoirs and release antibacterial metal ions or organic linkers; by constructing a porous structure, MOFs can act as carriers for multiple types of agents and achieve slow and sustained release; and by designing their composition and the pore structure precisely, MOFs can be endowed with properties to produce heat and free radicals under stimulation. Importantly, in combination with other materials, MOFs can act as a platform to kill bacteria effectively through the synergistic effect of multiple types of mechanisms. In this review, we focus on the recent development of MOF-based antibacterial agents, which are classified according to their antibacterial mechanisms.

Multistage-Responsive Nanocomplexes Attenuate Ulcerative Colitis by Improving the Accumulation and Distribution of Oral Nucleic Acid Drugs in the Colon

Oral gene therapy has emerged as a potential optimal treatment for ulcerative colitis (UC). Nucleic acid drugs possessing versatility can not only inhibit inflammation but realize colon mucosal healing, fulfilling the clinical objective of UC therapy. However, the effective accumulation and distribution of oral nucleic acid drugs in the colon remain a considerable challenge. Furthermore, current delivery systems pay more attention to the accumulation of nucleic acid drugs in the colon, while the distribution of nucleic acid drugs in the colon, which plays a key role in the UC treatment, never catches the attention of researchers. Here, we used miR-320 as a model nucleic acid drug to develop a kind of multistage-responsive nanocomplexes (MSNs) based on polymeric nanocapsules and alginate. MSNs possess the pH responsiveness in the stomach, the enzyme responsiveness in the colonic lumen, and the redox responsiveness in the cytoplasm. In vivo imaging results showed that MSNs reach the colon within 2 h and effectively release miR-320 nanocapsules in the colonic lumen. The nanocapsules can further deliver miR-320 to the submucosal layer and even the muscular layer. Moreover, MSNs decreased the activity of myeloperoxidase and proinflammatory cytokines and exhibited anti-inflammatory activity by inhibiting the phosphorylation of IκBα and AKT, reducing colonic inflammation and enhancing mucosal repair. Therefore, MSNs can successfully alleviate UC by improving the accumulation and distribution of oral nucleic acid drugs in the colon, promoting the clinical translational application of nucleic acid drugs in the treatment of UC.

Enzyme Therapeutic for Ischemia and Reperfusion Injury in Organ Transplantation

Ischemia-reperfusion injury (IRI) remains as a critical challenge for organ transplantation. Herein, an enzyme therapeutic based on superoxide dismutase and catalase for effective mitigation of IRI and pathogen-induced liver injury is reported, providing a therapeutic for organ transplantation and other diseases.

5'-tiRNA-Cys-GCA regulates VSMC proliferation and phenotypic transition by targeting STAT4 in aortic dissection

Accumulating evidence shows that tRNA-derived fragments are a novel class of functional small non-coding RNA; however, their roles in aortic dissection (AD) are still unknown. In this study, we found that 5'-tiRNA-Cys-GCA was significantly downregulated in human and mouse models of aortic dissection. The abnormal proliferation, migration, and phenotypic transition of vascular smooth muscle cells (VSMCs) played a crucial role in the initiation and progression of aortic dissection, with 5'-tiRNA-Cys-GCA as a potential phenotypic switching regulator, because its overexpression inhibited the proliferation and migration of VSMCs and increased the expression of contractile markers. In addition, we verified that signal transducer and activator of transcription 4 (STAT4) was a direct downstream target of 5'-tiRNA-Cys-GCA. We found that the STAT4 upregulation in oxidized low-density lipoprotein (ox-LDL)-treated VSMCs, which promoted cell proliferation, migration, and phenotypic transformation, was reversed by 5'-tiRNA-Cys-GCA. Furthermore, 5'-tiRNA-Cys-GCA treatment reduced the incidence and prevented the malignant process of angiotensin II- and β-aminopropionitrile-induced AD in mice. In conclusion, our findings reveal that 5'-tiRNA-Cys-GCA is a potential regulator of the AD pathological process via the STAT4 signaling pathway, providing a novel clinical target for the development of future treatment strategies for aortic dissection.

Mussel-Inspired Carboxymethyl Chitosan Hydrogel Coating of Titanium Alloy with Antibacterial and Bioactive Properties

Infection-related titanium implant failure rates remain exceedingly high in the clinic. Functional surface coating represents a very promising strategy to improve the antibacterial and bioactive properties of titanium alloy implants. Here, we describe a novel bioactive surface coating that consists of a mussel-inspired carboxymethyl chitosan hydrogel loaded with silver nanoparticles (AgNPs) to enhance the bioactive properties of the titanium alloy. The preparation of hydrogel is based on gallic acid grafted carboxymethyl chitosan (CMCS-GA) catalyzed by DMTMM (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride). To build a firm bonding between the hydrogel and titanium alloy plate, a polydopamine layer was introduced onto the surface of the titanium alloy. With HRP/H₂O₂ catalysis, CMCS-GA can simply form a firm gel layer on the titanium alloy plate through the catechol groups. The surface properties of titanium alloy were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and water contact angle. Silver nanoparticles were loaded into the gel layer by in situ reduction to enhance the antibacterial properties. In vitro antibacterial and cell viability experiments showed that the AgNPs-loaded Ti-gel possesses excellent antibacterial properties and did not affect the proliferation of rabbit mesenchymal stem cells (MSCs).

NanoZnO-modified titanium implants for enhanced anti-bacterial activity, osteogenesis and corrosion resistance

Titanium (Ti) implants are widely used in dentistry and orthopedics owing to their excellent corrosion resistance, biocompatibility, and mechanical properties, which have gained increasing attention from the viewpoints of fundamental research and practical applications. Also, numerous studies have been carried out to fine-tune the micro/nanostructures of Ti and/or incorporate chemical elements to improve overall implant performance. Zinc oxide nanoparticles (nano-ZnO) are well-known for their good antibacterial properties and low cytotoxicity along with their ability to synergize with a variety of substances, which have received increasingly widespread attention as biomodification materials for implants. In this review, we summarize recent research progress on nano-ZnO modified Ti-implants. Their preparation methods of nano-ZnO modified Ti-implants are introduced, followed by a further presentation of the antibacterial, osteogenic, and anti-corrosion properties of these implants. Finally, challenges and future opportunities for nano-ZnO modified Ti-implants are proposed.

Nanomedicines for the Efficient Treatment of Intracellular Bacteria: The "ART" Principle

Infections induced by bacteria at present are a severe threat to public health. Compared with extracellular bacteria, intracellular bacteria are harder to get rid of and readily induce chronic inflammation as well as autoimmune disorders. As the development of new antibiotics becomes more and more difficult, the construction of new antibiotic dosage forms is one of the optimal choices for the elimination of intracellular bacteria, and, to date, various nanomedicines have been exploited. However, current nanomedicines have limited treatment efficiency for intracellular bacteria due to the multiple biological barriers. Here in this short review, we focus on systemically administered nanomedicines and divide the treatment of intracellular bacteria with nanomedicines into three steps: 1) Accumulation at the infection site; 2) Recognition of infected cells; 3) Targeting of intracellular bacteria. Furthermore, we summarize how nanomedicines are elaborately designed to achieve the "ART" principle and discuss the problems of experimental models construction. Through this review, we want to remind that the golden approach for the building of cell and animal experimental models should be established, and nanomedicines should be also endowed with the versatility to follow the "ART" principle, efficiently improving the treatment efficiency of nanomedicines for intracellular bacteria.

Electrospinning Proteins for Wound Healing Purposes: Opportunities and Challenges

With the growth of the aging population worldwide, chronic wounds represent an increasing burden to healthcare systems. Wound healing is complex and not only affected by the patient's physiological conditions, but also by bacterial infections and inflammation, which delay wound closure and re-epithelialization. In recent years, there has been a growing interest for electrospun polymeric wound dressings with fiber diameters in the nano- and micrometer range. Such wound dressings display a number of properties, which support and accelerate wound healing. For instance, they provide physical and mechanical protection, exhibit a high surface area, allow gas exchange, are cytocompatible and biodegradable, resemble the structure of the native extracellular matrix, and deliver antibacterial agents locally into the wound. This review paper gives an overview on cytocompatible and biodegradable fibrous wound dressings obtained by electrospinning proteins and peptides of animal and plant origin in recent years. Focus is placed on the requirements for the fabrication of such drug delivery systems by electrospinning as well as their wound healing properties and therapeutic potential. Moreover, the incorporation of antimicrobial agents into the fibers or their attachment onto the fiber surface as well as their antimicrobial activity are discussed.