Science and technology have always been the vitals of human’s struggle, utilized exclusively for the development of novel tools and products, ranging from micro- to nanosize. Nanotechnology has gained significant attention due to its extensive applications in biomedicine, particularly related to bio imaging and drug delivery. Various nanodevices and nanomaterials have been developed for the diagnosis and treatment of different diseases. Herein, we have described two primary aspects of the nanomedicine, i.e., in vivo imaging and drug delivery, highlighting the recent advancements and future explorations. Tremendous advancements in the nanotechnology tools for the imaging, particularly of the cancer cells, have recently been observed. Nanoparticles offer a suitable medium to carryout molecular level modifications including the site-specific imaging and targeting. Invention of radionuclides, quantum dots, magnetic nanoparticles, and carbon nanotubes and use of gold nanoparticles in biosensors have revolutionized the field of imaging, resulting in easy understanding of the pathophysiology of disease, improved ability to diagnose and enhanced therapeutic delivery. This high specificity and selectivity of the nanomedicine is important, and thus, the recent advancements in this field need to be understood for a better today and a more prosperous future.

Methotrexate (MTX), the gold standard against psoriasis, poses severe problems when administered systemically viz increased toxicity, poor solubility and adverse reactions. Hence, a topical formulation of MTX for the management of psoriasis can be an effective approach. The present study aimed to develop an MTX based nanoparticle-loaded chitosan hydrogel for evaluating its potential efficacy in an imiquimod-induced psoriatic mice model. MTX-NPs loaded hydrogel was prepared and optimized using the o/w emulsion solvent evaporation method. Particle size, zeta potential, entrapment efficiency, in vitro drug release, ex vivo permeation, skin irritation and deposition studies were performed. Psoriatic Area and Severity Index (PASI) score/histopathological examinations were conducted to check the antipsoriatic potential of MTX-NPs loaded hydrogel using an imiquimod (IMQ)-induced psoriatic model. Optimized MTX-NPs showed a particle size of 256.4 ± 2.17 nm and encapsulation efficiency of 86 ± 0.03%. MTX-NPs loaded hydrogel displayed a 73 ± 1.21% sustained drug release in 48 h. Ex vivo permeation study showed only 19.95 ± 1.04 µg/cm² of drug permeated though skin in 24 h, while epidermis retained 81.33% of the drug. A significant decrease in PASI score with improvement to normalcy of mice skin was observed. The developed MTX-NPs hydrogel displayed negligible signs of mild hyperkeratosis and parakeratosis, while histopathological studies showed healing signs of mice skin. So, the MTX-NPs loaded hydrogel can be a promising delivery system against psoriasis.

Chronic wound infections have become a challenging problem due to escalating antibiotic resistance and lack of viable delivery approaches. Carvacrol (CAR) has been reported to be effective against multidrug resistant pathogens. In this study, CAR was formulated into a site-specific nanoparticle (NP) delivery system using poly(caprolactone) (PCL) to achieve a sustained antimicrobial effect at infection sites. These NPs were further incorporated into dissolving microneedles (MNs) to facilitate painless application and overcome the necrotic tissue barrier which hinders drug penetration into wound bed. The release study exhibited significantly higher release of CAR from PCL NPs in the presence of bacteria, highlighting its potential for on-demand delivery. Moreover, encapsulation of CAR in PCL NPs resulted in 2-4 fold increase in its antimicrobial activity. Dermatokinetic studies revealed that CAR-PCL NPs-MNs were able to enhance skin retention of CAR after 24 h (83.8 ± 5.15%), compared to free CAR-MNs (7.3 ± 2.04%). Importantly, this novel approach exhibited effective antimicrobial activity in an ex-vivo wound model. Hence, these findings have proven the concept that loading of CAR into this advanced MNs platform can lead to sustained antimicrobial effect at desired site and may provide a novel effective approach for treatment of infected wounds. However, further studies must be conducted to investigate in-vivo efficacy of the developed system in an appropriate infection model.