Study and Evaluation of the Potential of Lipid Nanocarriers for Transdermal Delivery of siRNA

Reconnoitring signaling pathways and exploiting innovative approaches tailoring multifaceted therapies for skin cancer

Nowadays, skin cancer is widespread just like a varied malignant cancer which can cause serious health issues. Skin cancer, which encompasses malignant melanoma, basal cell carcinoma, and squamous cell carcinoma, is a prevalent form of cancer among humans. Due to its broad prevalence, financial burden, mortality rates, and cosmetic effects, it is a major public health issue. Skin cancer treatment involves surgery, chemotherapy, and radiation. Recently, personalized treatment in the fields of targeted therapies and precision medicine has been shown to diagnose early detection of every individual tumor by knowing their genetic and molecular characteristics. To target the molecular pathways responsible for tumor growth and reduce the damage to healthy tissue, new targeted therapies have emerged for melanoma, basal cell carcinoma, and squamous cell carcinoma. B-raf serine/threonine kinase (BRAF) and mitogen-activated protein kinase (MEK) inhibitors, immune checkpoint inhibitors, and precision medications have strong response rates to improve patient survival. Targeted therapeutics like nanocarriers have shown promising results by reducing skin irritation and protecting encapsulated therapeutics. These formulations have been shown to improve the transdermal permeability of anticancer drugs. The consideration of employing physical techniques to enhance the permeation of nanocarriers warrants attention to augment the dermal permeation of anticancer agents and facilitate targeted drug delivery within neoplastic cells. Targeted therapies face obstacles like resistance mechanisms and treatment strategy monitoring. Taken together, this review delves into the basic mechanisms of skin cancer, current treatment methods, drug resistance processes, and nano-based targeted techniques for cancer treatment. It will also delineate the challenges and perspectives in pre-clinical and clinical contexts.

RNA-binding peptide and endosomal escape-assisting peptide (L2) improved siRNA delivery by the hexahistidine-metal assembly

Small interfering RNAs (siRNAs), comprising 21-23 nucleotides, function by complementary binding to specific mRNA sequences, thereby suppressing target protein expression. Despite their vast potential in disease therapy, siRNAs face challenges due to their susceptibility to degradation and high electronegativity, rendering them unstable in the bloodstream and impeding their passage across endothelial barriers. Moreover, successful intracellular delivery necessitates overcoming endosomal entrapment, posing a significant hurdle for carrier material development. In this study, leveraging the strong affinity of histidine oligomers (His6) for metal ions, we engineered nanoparticles (HmA) by gentle assembly with divalent zinc ions under pH = 8 conditions. We designed the RNA-binding functional peptide L2-NTD to enhance siRNA stability and delivery efficiency when complexed with HmA. The resulting siRNA+L2-NTD@HmA nanoparticles were formed via in situ encapsulation, ensuring efficient siRNA delivery into cells with minimal cytotoxicity and degradation. This approach presents a novel strategy for the design and artificial fabrication of carriers for effective RNA delivery.

RNAi-based drug design: considerations and future directions

More than 25 years after its discovery, the post-transcriptional gene regulation mechanism termed RNAi is now transforming pharmaceutical development, proved by the recent FDA approval of multiple small interfering RNA (siRNA) drugs that target the liver. Synthetic siRNAs that trigger RNAi have the potential to specifically silence virtually any therapeutic target with unprecedented potency and durability. Bringing this innovative class of medicines to patients, however, has been riddled with substantial challenges, with delivery issues at the forefront. Several classes of siRNA drug are under clinical evaluation, but their utility in treating extrahepatic diseases remains limited, demanding continued innovation. In this Review, we discuss principal considerations and future directions in the design of therapeutic siRNAs, with a particular emphasis on chemistry, the application of informatics, delivery strategies and the importance of careful target selection, which together influence therapeutic success.

TMEM232 promotes the inflammatory response in atopic dermatitis via the nuclear factor-κB and signal transducer and activator of transcription 3 signalling pathways

BACKGROUND

Our group previously found that the transmembrane protein 232 (TMEM232) gene was associated with atopic dermatitis (AD) by genome-wide association study and fine mapping study. However, its function is unclear so far.

OBJECTIVES

To investigate the roles and mechanisms of TMEM232 in AD.

METHODS

The expression of TMEM232 was investigated in skin lesions of patients with AD, the MC903-induced AD mouse model, human primary keratinocytes and immortalized human keratinocyte cell line (HaCaT) cells stimulated with different inflammatory factors. The role of TMEM232 in AD was analysed in HaCaT cells and Tmem232 knockout (Tmem232-/-) mice. Tmem232-specific small interfering RNA (siRNA) was used to evaluate its therapeutic potential in the AD mouse model.

RESULTS

The expression of TMEM232 was significantly increased in skin lesions of patients with AD, the MC903-induced AD mouse model and human primary keratinocytes and HaCaT cells stimulated with different inflammatory factors compared with controls. In the presence of MC903, Tmem232-/- mice exhibited significantly reduced dermatitis severity, mast-cell infiltration in the back, and expression of T-helper (Th)1 and Th2-related inflammatory factors in skin tissue compared with wild-type mice. In vitro and in vivo experiments further showed that upregulation of TMEM232 in AD exacerbated the inflammation response through activating the pathway of nuclear factor-κB and signal transducer and activator of transcription (STAT) 3, and was regulated by the interleukin-4/STAT6 axis, which formed a self-amplifying loop. Finally, topical application of Tmem232 siRNA markedly ameliorated AD-like lesions in the AD model.

CONCLUSIONS

This study is the first to outline the function of TMEM232. It is involved in regulating inflammation in AD and may be a potential target for AD treatment.

Combinational System of Lipid-Based Nanocarriers and Biodegradable Polymers for Wound Healing: An Updated Review

Skin wounds have imposed serious socioeconomic burdens on healthcare providers and patients. There are just more than 25,000 burn injury-related deaths reported each year. Conventional treatments do not often allow the re-establishment of the function of affected regions and structures, resulting in dehydration and wound infections. Many nanocarriers, such as lipid-based systems or biobased and biodegradable polymers and their associated platforms, are favorable in wound healing due to their ability to promote cell adhesion and migration, thus improving wound healing and reducing scarring. Hence, many researchers have focused on developing new wound dressings based on such compounds with desirable effects. However, when applied in wound healing, some problems occur, such as the high cost of public health, novel treatments emphasizing reduced healthcare costs, and increasing quality of treatment outcomes. The integrated hybrid systems of lipid-based nanocarriers (LNCs) and polymer-based systems can be promising as the solution for the above problems in the wound healing process. Furthermore, novel drug delivery systems showed more effective release of therapeutic agents, suitable mimicking of the physiological environment, and improvement in the function of the single system. This review highlights recent advances in lipid-based systems and the role of lipid-based carriers and biodegradable polymers in wound healing.

Simultaneous quantification of oligo-nucleic acids and a ferritin nanocage by size-exclusion chromatography hyphenated to inductively coupled plasma mass spectrometry for developing drug delivery systems

An analytical methodology, which can quantify nucleic acids, ferritin nanocages, and their complexes in a single injection, was established by means of size-exclusion chromatography hyphenated with inductively coupled plasma mass spectrometry (SEC-ICP-MS). In this study, several oligo-nucleic acids and ferritin (a human-derived cage-shaped protein) were used as model compounds of nucleic acid drugs (NAD) and drug delivery system (DDS) carriers, respectively. A fraction based on the nucleic acid-ferritin complex was completely distinguished from one based on free nucleic acids by SEC separation. The nucleic acids and ferritin were quantified based on the number of phosphorus and sulfur atoms, respectively. The quantification was carried out by an external calibration method using a series of elemental standard solutions without preparing designated standard materials for each drug candidate. The analytical performance, including sensitivity and accuracy, was evaluated to be appropriate for evaluating the medicines already launched in the market. As demonstrated in the latter part of this study, the encapsulation mechanism is possibly regulated by not only the averaged molecular size of nucleic acids but also the surface charge related to the number of (deoxy-) ribonucleotides. We believe that the methodology presented in this study has the potential to accelerate the development of new modalities based on NAD-DDS to realize therapies in the future.

Transdermal delivery of poly-hyaluronic acid-based spherical nucleic acids for chemogene therapy

Spherical nucleic acid (SNA), as a good gene delivery system, has a good application prospect for transdermal administration in skin disorder treatment. However, most of the traditional SNA core materials are non-degradable materials, so it is worthy of further research. Herein, we report a spherical nucleic acid based on poly-hyaluronic acid (PHA) for the co-delivery of a typical chemotherapeutic drug, doxorubicin (DOX), and an antisense oligonucleotide (ASO) against the tissue inhibitor of metalloproteinases 1 (TIMP-1) for the treatment of hypertrophic scars (HS) which are caused by abnormal fibroblast proliferation. Our study showed that PHA-based SNAs simultaneously bearing TIMP-1 ASO and DOX (termed PHAAD) could significantly promote skin penetration, improve the cellular uptake, and effectively down-regulate the TIMP-1 expression and enhance the cytotoxicity of DOX. Moreover, PHAAD nanoparticles facilitated the apoptosis of hypertrophic scar cells, and reduced the burden and progression of hypertrophic scars in a xenografted mouse model without adverse side effects. Thus, our PHA-based SNA represents a new transdermal delivery vehicle for efficient combinatorial chemo and gene therapy, which is expected to treat various skin disorders.

Transdermal delivery for gene therapy

Gene therapy is a critical constituent of treatment approaches for genetic diseases and has gained tremendous attention. Treating and preventing diseases at the genetic level using genetic materials such as DNA or RNAs could be a new avenue in medicine. However, delivering genes is always a challenge as these molecules are sensitive to various enzymes inside the body, often produce systemic toxicity, and suffer from off-targeting problems. In this regard, transdermal delivery has emerged as an appealing approach to enable a high efficiency and low toxicity of genetic medicines. This review systematically summarizes outstanding transdermal gene delivery methods for applications in skin cancer treatment, vaccination, wound healing, and other therapies.

Formulation-based approaches for dermal delivery of vaccines and therapeutic nucleic acids: Recent advances and future perspectives

A growing variety of biological macromolecules are in development for use as active ingredients in topical therapies and vaccines. Dermal delivery of biomacromolecules offers several advantages compared to other delivery methods, including improved targetability, reduced systemic toxicity, and decreased degradation of drugs. However, this route of delivery is hampered by the barrier function of the skin. Recently, a large body of research has been directed toward improving the delivery of macromolecules to the skin, ranging from nucleic acids (NAs) to antigens, using noninvasive means. In this review, we discuss the latest formulation-based efforts to deliver antigens and NAs for vaccination and treatment of skin diseases. We provide a perspective of their advantages, limitations, and potential for clinical translation. The delivery platforms discussed in this review may provide formulation scientists and clinicians with a better vision of the alternatives for dermal delivery of biomacromolecules, which may facilitate the development of new patient-friendly prophylactic and therapeutic medicines.