Delivery and targeting of nanoparticles into hair follicles
Nanoparticles can be effective drug delivery systems for penetrating into hair follicles. It has been demonstrated that nanoparticles used for follicular delivery provide some advantages over conventional pathways, including improved skin bioavailability, enhanced penetration depth, prolonged residence duration, fast transport into the skin, and tissue targeting. In recent years the concept of using nanoparticles to treat follicle-related diseases has attracted increasing attention. Different types of nanosystems may be employed for management of follicular permeation, such as polymeric nanoparticles, metallic nanocrystals, liposomes, and lipid nanoparticles. We investigates the mechanisms of follicles for nanoparticulate penetration, highlighting the therapeutic potential of drug-loaded nanoparticles for treating skin diseases. Special attention is paid to the use of nanoparticles in treating appendage-related disorders, in particular, nanomedical strategies for treating alopecia, acne, and transcutaneous immunization. Issues related to the possible risk of nanoparticulate entry into the skin that may induce a toxicity concern are also discussed. Future progress and the possible advances of follicle-mediated nanoparticle delivery are anticipated.
Injectable nanocarrier delivery to lungs for drug therapy
Different types of injectable nanoparticles, including metallic nanoparticles, polymeric nanocarriers, dendrimers, liposomes, niosomes, and lipid nanoparticles, have been employed to load drugs for lung delivery. Nanoparticles used for lung delivery offer some benefits over conventional formulations, including increased solubility, enhanced stability, improved epithelium permeability and bioavailability, prolonged half-life, tumor targeting, and minimal side effects. In recent years, the concept of using injectable nanocarriers as vehicles for drug delivery has attracted increasing attention. We systematically investigate the concepts and amelioration mechanisms of the nanomedical techniques for lung-disease therapy. These modalities are useful in the treatment of a wide variety of lung disorders including lung carcinoma, tumor metastasis to the lungs, pulmonary vascular diseases, lung infection, and acute inflammation. Passive targeting by modulating the nanoparticulate structure and the physicochemical properties is an option for efficient drug delivery to the lungs. In addition, active targeting such as antibody or peptide conjugation to nanoparticles is another efficient way to deliver the drugs to the targeted site. We principally focus on the nanomedical application in animal studies.
Nanomedical strategies for treating drug-resistant microbiomes
Nanoparticles can be effective drug delivery systems for treating bacterial and fungal infections. It has been demonstrated that nanoparticles used for drug therapy provide some advantages over conventional formulations, including increased solubility, enhanced storage stability, improved permeability and bioavailability, prolonged half-life, tissue targeting, and minimal side effects. In recent years the concept of using nanoparticles to treat drug-resistant microbiome-related diseases has attracted increasing attention. Different types of nanosystems may be employed for antimicrobial management of disease, such as liposomes, microemulsions, solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), and polymeric nanoparticles. We systematically study the structures and physicochemical properties of various nanocarriers, highlighting the antibacterial potential of nanoparticles for inhibiting infection. Special attention is paid to the use of nanoparticles in treating skin and appendageal bacteria, in particular, nanomedical strategies for treating cutaneous infection and acne. Issues related to treatment of non-appendageal bacteria and fungi are also investigated.
Lasers as a strategy for promoting drug delivery via skin
Using lasers can be an effective drug-permeation-enhancement approach for facilitating drug delivery into or across the skin. The controlled disruption and ablation of the stratum corneum (SC), the predominant barrier for drug delivery, is achieved by the use of lasers. The possible mechanisms of laser-assisted drug permeation are the direct ablation of the skin barrier, optical breakdown by a photomechanical wave (PW), and a photothermal effect. It has been demonstrated that ablative approaches for enhancing drug transport provide some advantages, including increased bioavailability, fast treatment time, quick recovery of SC integrity, and the fact that skin surface contact is not needed. In recent years, the concept of using laser techniques to treat the skin has attracted increasing attention. Lasers with different wavelengths and types are employed to increase drug permeation. These include the ruby laser, the erbium:yttrium-gallium-garnet (Er:YAG) laser, the Nd:YAG laser, the CO2 laser, and the fractional laser. The laser modality is useful to enhance the permeation of a wide variety of permeants, such as small-molecule drugs, macromolecules, and nanoparticles. This potential use of the laser affords a new treatment for topical/transdermal application with significant efficacy. Further studies using a large group for humans or patients are needed to confirm and clarify the findings in animal studies. Although the laser fluence or output energy used for enhancing drug absorption is much lower than for treatment of skin disorders and rejuvenation, the safety of using lasers is still an issue. Caution should be used in optimizing the feasible conditions of the lasers in balancing the effectiveness of permeation enhancement and skin damage.
Noninvasive approach for enhancing small interfering RNA delivery percutaneously
Topically applied small interfering RNA (siRNA) can be an effective treatment for skin disorders. Using noninvasive strategies can be a safe and effective siRNA-permeation-enhancement approach for facilitating skin delivery. It has been demonstrated that noninvasive approaches for enhancing siRNA transport provide some advantages, including enhanced storage stability, targeted delivery, improved permeability and increased bioavailability. In recent years, the concept of using noninvasive enhancement techniques to promote RNA interference (RNAi) therapy for cutaneous disorders has attracted increasing attention. These techniques include: nanomedicine, penetration enhancers, matrix-based delivery, microneedles, iontophoresis, electroporation and lasers. These modalities are useful for enhancing the permeation of a wide variety of siRNA for treating skin cancers, gene-related diseases, immune-related diseases and cutaneous wounds. The potential use of the noninvasive approaches affords a new treatment for topical siRNA application with significant efficacy. Further studies using a large group for humans or patients are needed to confirm and clarify the findings in animal studies. Although a safe and non-toxic outcome is claimed, the possible adverse effects and irritation elicited by the noninvasive techniques cannot be ignored. Caution should be used in optimizing the feasible conditions of the approaches in balancing the effectiveness of permeation enhancement and skin disruption.
The codrug approach for facilitating bioactivity and drug delivery
Codrug or mutual prodrug is a drug design approach to chemically bind two or more drugs to improve therapeutic efficiency or decrease adverse effects. The codrug can be cleaved in the body to generate parent actives. The codrug itself can be inactive, less active, or more active than the parent agents. It has been demonstrated that codrugs possess some benefits over conventional drugs, including enhanced solubility, increased permeation for passing across biomembranes, prolonged half-life for extending the therapeutic period, and reduced toxicity. Codrugs are predominantly used to treat some conditions such as neurodegenerative, cardiovascular, cancerous, infectious, and inflammatory disorders. Many codrugs are developed to increase lipophilicity for better transport into/across biomembranes, especially the skin and cornea. A targeted delivery of codrugs to specific tissues or organs thus can be achieved to promote bioavailability. The chemical and enzymatic hydrolysis, bioactivity, and pharmacokinetics of codrugs are systematically explored in our laboratory. Additional profiles pertaining to clinical trials will support further applicability of codrug therapy.