Enhanced stability and clinical absorption of a form of encapsulated vitamin A for food fortification.

Food fortification is an effective strategy to address vitamin A (VitA) deficiency, which is the leading cause of childhood blindness and drastically increases mortality from severe infections. However, VitA food fortification remains challenging due to significant degradation during storage and cooking. We utilized an FDA-approved, thermostable, and pH-responsive basic methacrylate copolymer (BMC) to encapsulate and stabilize VitA in microparticles (MPs). Encapsulation of VitA in VitA-BMC MPs greatly improved stability during simulated cooking conditions and long-term storage. VitA absorption was nine times greater from cooked MPs than from cooked free VitA in rats. In a randomized controlled cross-over study in healthy premenopausal women, VitA was readily released from MPs after consumption and had a similar absorption profile to free VitA. This VitA encapsulation technology will enable global food fortification strategies toward eliminating VitA deficiency.

Stabilized single-injection inactivated polio vaccine elicits a strong neutralizing immune response.

Vaccination in the developing world is hampered by limited patient access, which prevents individuals from receiving the multiple injections necessary for protective immunity. Here, we developed an injectable microparticle formulation of the inactivated polio vaccine (IPV) that releases multiple pulses of stable antigen over time. To accomplish this, we established an IPV stabilization strategy using cationic polymers for pH modulation to enhance traditional small-molecule-based stabilization methods. We investigated the mechanism of this strategy and showed that it was broadly applicable to all three antigens in IPV. Our lead formulations released two bursts of IPV 1 month apart, mimicking a typical vaccination schedule in the developing world. One injection of the controlled-release formulations elicited a similar or better neutralizing response in rats, considered the correlate of protection in humans, than multiple injections of liquid vaccine. This single-administration vaccine strategy has the potential to improve vaccine coverage in the developing world.

Quantitative self-assembly prediction yields targeted nanomedicines.

Development of targeted nanoparticle drug carriers often requires complex synthetic schemes involving both supramolecular self-assembly and chemical modification. These processes are generally difficult to predict, execute, and control. We describe herein a targeted drug delivery system that is accurately and quantitatively predicted to self-assemble into nanoparticles based on the molecular structures of precursor molecules, which are the drugs themselves. The drugs assemble with the aid of sulfated indocyanines into particles with ultrahigh drug loadings of up to 90%. We devised quantitative structure-nanoparticle assembly prediction (QSNAP) models to identify and validate electrotopological molecular descriptors as highly predictive indicators of nano-assembly and nanoparticle size. The resulting nanoparticles selectively targeted kinase inhibitors to caveolin-1-expressing human colon cancer and autochthonous liver cancer models to yield striking therapeutic effects while avoiding pERK inhibition in healthy skin. This finding enables the computational design of nanomedicines based on quantitative models for drug payload selection.

Toxicological assessment and food allergy of silk fibroin derived from Bombyx mori cocoons.

Recent studies have demonstrated silk fibroin protein's (SF) ability to extend the shelf life of foods by mitigating the hallmarks of spoilage, namely oxidation and dehydration. Due to the potential for this protein to become more widespread, its safety was evaluated comprehensively. First, a bacterial reverse mutation test (Ames test) was conducted in five bacterial strains. Second, an in vivo erythrocyte test was conducted with Sprague Dawley rats at doses up to 1,000mg/kg-bw/day. Third, a range-finder study was conducted with Sprague Dawley rats at the highest consumption amount given solubility and oral gavage volume constrains (500mg/kg-bw/day). Fourth, a 28-day sub-chronic study in Sprague Dawley rats was conducted with the high dose set at 500mg/kg-bw/day, as limited by solubility of the protein in a single-gavage per-day study. Fifth, an in vitro pepsin digestion assay was performed to assess the potential for protein allergenicity. Sixth, allergenic potential was further assessed using liquid chromatography-mass spectroscopy for detection of allergenic insect proteins. Seventh, the SF protein sequences were subjected to bioinformatic analyses. Together, these studies raise no mutagenic, genotoxic, toxicological, or allergenic concerns with the oral consumption of silk fibroin.

Biocompatible near-infrared quantum dots delivered to the skin by microneedle patches record vaccination.

Accurate medical recordkeeping is a major challenge in many low-resource settings where well-maintained centralized databases do not exist, contributing to 1.5 million vaccine-preventable deaths annually. Here, we present an approach to encode medical history on a patient using the spatial distribution of biocompatible, near-infrared quantum dots (NIR QDs) in the dermis. QDs are invisible to the naked eye yet detectable when exposed to NIR light. QDs with a copper indium selenide core and aluminum-doped zinc sulfide shell were tuned to emit in the NIR spectrum by controlling stoichiometry and shelling time. The formulation showing the greatest resistance to photobleaching after simulated sunlight exposure (5-year equivalence) through pigmented human skin was encapsulated in microparticles for use in vivo. In parallel, microneedle geometry was optimized in silico and validated ex vivo using porcine and synthetic human skin. QD-containing microparticles were then embedded in dissolvable microneedles and administered to rats with or without a vaccine. Longitudinal in vivo imaging using a smartphone adapted to detect NIR light demonstrated that microneedle-delivered QD patterns remained bright and could be accurately identified using a machine learning algorithm 9 months after application. In addition, codelivery with inactivated poliovirus vaccine produced neutralizing antibody titers above the threshold considered protective. These findings suggest that intradermal QDs can be used to reliably encode information and can be delivered with a vaccine, which may be particularly valuable in the developing world and open up new avenues for decentralized data storage and biosensing.

A heat-stable microparticle platform for oral micronutrient delivery.

Micronutrient deficiencies affect up to 2 billion people and are the leading cause of cognitive and physical disorders in the developing world. Food fortification is effective in treating micronutrient deficiencies; however, its global implementation has been limited by technical challenges in maintaining micronutrient stability during cooking and storage. We hypothesized that polymer-based encapsulation could address this and facilitate micronutrient absorption. We identified poly(butylmethacrylate-co-(2-dimethylaminoethyl)methacrylate-co-methylmethacrylate) (1:2:1) (BMC) as a material with proven safety, offering stability in boiling water, rapid dissolution in gastric acid, and the ability to encapsulate distinct micronutrients. We encapsulated 11 micronutrients (iron; iodine; zinc; and vitamins A, B2, niacin, biotin, folic acid, B12, C, and D) and co-encapsulated up to 4 micronutrients. Encapsulation improved micronutrient stability against heat, light, moisture, and oxidation. Rodent studies confirmed rapid micronutrient release in the stomach and intestinal absorption. Bioavailability of iron from microparticles, compared to free iron, was lower in an initial human study. An organotypic human intestinal model revealed that increased iron loading and decreased polymer content would improve absorption. Using process development approaches capable of kilogram-scale synthesis, we increased iron loading more than 30-fold. Scaled batches tested in a follow-up human study exhibited up to 89% relative iron bioavailability compared to free iron. Collectively, these studies describe a broad approach for clinical translation of a heat-stable ingestible micronutrient delivery platform with the potential to improve micronutrient deficiency in the developing world. These approaches could potentially be applied toward clinical translation of other materials, such as natural polymers, for encapsulation and oral delivery of micronutrients.

Evaporative Cooling Hydrogel Packaging for Storing Biologics Outside of the Cold Chain.

Stabilizing thermolabile pharmaceuticals outside of the cold chain has the potential to alleviate some of the logistical and monetary burden of providing health care access in the developing world. Evaporative cooling hydrogel packaging is designed to extend the storage stability of existing pharmaceutical products without the need for reformulation. Hydrogels with high water content and reversible hydrophilicity offer a promising platform for reducing storage temperatures without refrigeration. As a model, poly(N-isopropylacrylamide) is selected as a basis for creating a potentially low cost and easy-to-fabricate hydrogels.