Programmable Self-Regulation with Wrinkled Hydrogels and Plasmonic Nanoparticle Lattices.

This paper describes a self-regulating system that combines wrinkle-patterned hydrogels with plasmonic nanoparticle (NP) lattices. In the feedback loop, the wrinkle patterns flatten in response to moisture, which then allows light to reach the NP lattice on the bottom layer. Upon light absorption, the NP lattice produces a photothermal effect that dries the hydrogel, and the system then returns to the initial wrinkled configuration. The timescale of this regulatory cycle can be programmed by tuning the degree of photothermal heating by NP size and substrate material. Time-dependent finite element analysis reveals the thermal and mechanical mechanisms of wrinkle formation. This self-regulating system couples morphological, optical, and thermo-mechanical properties of different materials components and offers promising design principles for future smart systems.

Morphological features of single cells enable accurate automated classification of cancer from non-cancer cell lines.

Accurate cancer detection and diagnosis is of utmost importance for reliable drug-response prediction. Successful cancer characterization relies on both genetic analysis and histological scans from tumor biopsies. It is known that the cytoskeleton is significantly altered in cancer, as cellular structure dynamically remodels to promote proliferation, migration, and metastasis. We exploited these structural differences with supervised feature extraction methods to introduce an algorithm that could distinguish cancer from non-cancer cells presented in high-resolution, single cell images. In this paper, we successfully identified the features with the most discriminatory power to successfully predict cell type with as few as 100 cells per cell line. This trait overcomes a key barrier of machine learning methodologies: insufficient data. Furthermore, normalizing cell shape via microcontact printing on self-assembled monolayers enabled better discrimination of cell lines with difficult-to-distinguish phenotypes. Classification accuracy remained robust as we tested dissimilar cell lines across various tissue origins, which supports the generalizability of our algorithm.

Facilitation of transscleral drug delivery by drug loaded magnetic polymeric particles.

A unique method was used to facilitate ocular drug delivery from periocular route by drug loaded magnetic sensitive particles. Injection of particles in periocular space along the eye axis followed by application of magnetic field in front of the eye would trigger the magnetic polymeric particles to move along the direction of magnetic force and reside against the outer surface of the sclera. This technique prevents removal of drug in the periocular space, observed in conventional transscleral drug delivery systems and hence higher amount of drug can enter the eye in a longer period of time. The experiments were performed by fresh human sclera and an experimental setup. Experimental setup was designed by side by side diffusion cell and hydrodynamic and thermal simulation of the posterior segment of the eye were applied. Magnetic polymeric particles were synthesized by alginate as a model polymer, iron oxide nanoparticles as a magnetic agent and diclofenac sodium as a model drug and characterized by SEM, TEM, DLS and FT-IR techniques. According to the SEM images, the size range of particles is around 60 to 800nm. The results revealed that the cumulative drug transfer from magnetic sensitive particles across the sclera improves by 70% in the presence of magnetic field. The results of this research show promising method of drug delivery to use magnetic properties to facilitate drug delivery to the back of the eye.

Challenges and Future Prospects for the Delivery of Biologics: Oral Mucosal, Pulmonary, and Transdermal Routes.

Biologic products are large molecules such as proteins, peptides, nucleic acids, etc., which have already produced many new drugs for clinical use in the last decades. Due to the inherent challenges faced by biologics after oral administration (e.g., acidic stomach pH, digestive enzymes, and limited permeation through the gastrointestinal tract), several alternative routes of administration have been investigated to enable sufficient drug absorption into systemic circulation. This review describes the buccal, sublingual, pulmonary, and transdermal routes of administration for biologics with relevant details of the respective barriers. While all these routes avoid transit through the gastrointestinal tract, each has its own strengths and weaknesses that may be optimal for specific classes of compounds. Buccal and sublingual delivery enable rapid drug uptake through a relatively permeable barrier but are limited by small epithelial surface area, stratified epithelia, and the practical complexities of maintaining a drug delivery system in the mouth. Pulmonary delivery accesses the highly permeable and large surface area of the alveolar epithelium but must overcome the complexities of safe and effective delivery to the alveoli deep in the lung. Transdermal delivery offers convenient access to the body for extended-release delivery via the skin surface but requires the use of novel devices and formulations to overcome the skin's formidable stratum corneum barrier. New technologies and strategies advanced to overcome these challenges are reviewed, and critical views in future developments of each route are given.