Collagen-Based Dissolving Microneedles with Flexible Pedestals: A Transdermal Delivery System for Both Anti-Aging and Skin Diseases.

Biocompatible polymer microneedles (MNs) are emerging as a promising platform for transdermal drug delivery, especially for facial treatments. Therefore, an MN patch in this study uses hydrolyzed collagen (HC) contained in skin cells as the main raw material and adopts a two-step cast method to develop a rapidly dissolving microneedle (DMN) to deliver collagen in a simple and minimally invasive way, allowing the release of the encapsulated drug in the skin. By optimizing the formulation and proportion of HC and auxiliary support materials, the mechanical strength required to pierce the skin is obtained, while the soft pedestal allows for flexibility in application. The DMNs can dissolve completely in the skin within 15 min and release within ≈ 8 h, and do not cause toxicity or irritation when being applied. In contrast to the ineffectiveness of oral and external application, and the high risk of dermal injection, drug-loaded DMNs overcome the drawbacks of traditional methods with direct penetration and minimally invasive manner, enabling efficient and safe treatment. The successful preparation and research of HC DMNs have innovative and practical significance in this field, and it is expected to become a simple, effective, and popular transdermal drug delivery platform for cosmetics.

Application of curcumin nanoformulations in Alzheimer's disease: prevention, diagnosis and treatment.

Objectives: Alzheimer's disease (AD) is a serious neurodegenerative disease. Although many therapeutic strategies have been studied, their clinical applications are immature. Moreover, these methods can only alleviate symptoms rather than cure it, posing a challenge to brain health in older adults worldwide. Curcumin (CUR) is a very promising natural compound for nerve protection and treatment. It can prevent and treat AD, and on the other hand, its fluorescence properties can be used in the diagnosis of AD. However, CUR is characterized by very low water solubility, fluid instability, rapid metabolism, low bioavailability and difficulty in penetrating the biological barriers, which limit its application. Nanocarriers are a potential material to improve the biocompatibility of CUR and its ability to cross biological barriers. Therefore, delivering CUR by nanocarriers is an effective method to achieve better efficacy. Methods: In this review, the preventive, therapeutic and diagnostic effects of CUR nanoformulations on AD, as well as various patents, clinical trials and experimental research progress in this field are discussed. The aim is to provide detailed reference and practical suggestions for future research. Results: CUR has a variety of pharmacological activities in the prevention and treatment of AD, and its nanoformulation can effectively improve solubility, bioavailability and the ability to penetrate the blood-brain barrier. Significant benefits have been observed in the current study. Discussion: CUR formulations have a good prospect in the prevention, diagnosis and treatment of AD, but the safety and principle of its administration need more detailed study in the future.

Microneedles-mediated drug delivery system for the diagnosis and treatment of melanoma.

As an emerging novel drug delivery system, microneedles (MNs) have a wide range of applications in the medical field. They can overcome the physiological barriers of the skin, penetrate the outermost skin of the human body, and form hundreds of reversible microchannels to enhance the penetration of drugs and deliver drugs to the diseased sites. So they have great applications in the diagnosis and treatment of melanoma. Melanoma is a kind of malignant tumor, the survival rate of patients with metastases is extremely low. The traditional methods of surgery and drug treatment for melanoma are often accompanied by large adverse reactions in the whole body, and the drug concentration is low. The use of MNs for transdermal administration can increase the drug concentration, reduce adverse reactions in the treatment process, and have good therapeutic effect on melanoma. This paper introduced various types of MNs and their preparation methods, summarized the diagnosis and various treatment options for melanoma with MNs, focused on the treatment of melanoma with dissolved MNs, and made prospect of MNs-mediated transdermal drug delivery in the treatment of melanoma.

Multimodal therapy strategies based on hydrogels for the repair of spinal cord injury.

Spinal cord injury (SCI) is a serious traumatic disease of the central nervous system, which can give rise to the loss of motor and sensory function. Due to its complex pathological mechanism, the treatment of this disease still faces a huge challenge. Hydrogels with good biocompatibility and biodegradability can well imitate the extracellular matrix in the microenvironment of spinal cord. Hydrogels have been regarded as promising SCI repair material in recent years and continuous studies have confirmed that hydrogel-based therapy can effectively eliminate inflammation and promote spinal cord repair and regeneration to improve SCI. In this review, hydrogel-based multimodal therapeutic strategies to repair SCI are provided, and a combination of hydrogel scaffolds and other therapeutic modalities are discussed, with particular emphasis on the repair mechanism of SCI.

Synthesis and characterization of ionic liquid microneedle patches with different carbon chain lengths for antibacterial application.

The prevention of bacterial infection is becoming more and more important in clinical medicine. Ionic liquids (ILs) can change the structure in an almost infinite way to actively antagonize pathogenic microorganism strains. The current biological materials of skin dressings inevitably have the shortcomings of single drug delivery form and low drug loading, which limit the practical application of skin dressings. Therefore, it is particularly important to develop drug delivery forms that can meet different conditions. The addition of ILs into crosslinked microneedle (MN) patches is a novel design scheme of MNs. The broad-spectrum antibacterial properties of imidazolium salt ILs ensure that the wound skin is sterile after the use of MN patches on the skin to open channels for drug delivery. In this study, imidazole IL monomers with different carbon chain lengths and the corresponding IL-MN patches were designed and synthesized. By comparing the antibacterial properties of four imidazolium salt IL monomers with different carbon chain lengths and the corresponding ionic liquid microneedle patches, we found that the antibacterial properties of IL monomers and IL-MN patches increased with the increase of substituent carbon chain lengths. Imidazole IL monomers have excellent antibacterial properties, which may be caused by the electrostatic interaction between the cations in the IL monomers and the anions in the bacterial membrane and the hydrophilic and hydrophobic interactions between the IL monomers.