A Biopharmaceutical Perspective on Higher-Order Structure and Thermal Stability of mRNA Vaccines.

Preservation of the integrity of macromolecular higher-order structure is a tenet central to achieving biologic drug and vaccine product stability toward manufacturing, distribution, storage, handling, and administration. Given that mRNA lipid nanoparticles (mRNA-LNPs) are held together by an intricate ensemble of weak forces, there are some intriguing parallels to biologic drugs, at least at first glance. However, mRNA vaccines are not without unique formulation and stabilization challenges derived from the instability of unmodified mRNA and its limited history as a drug or vaccine.

Encapsulation state of messenger RNA inside lipid nanoparticles.

Understanding the structure of messenger RNA (mRNA) lipid nanoparticles, and specifically the microenvironment of the mRNA molecules within these entities, is fundamental to advancing their biomedical potential. Here, we show that a permeating cationic dye, thionine, can serve as a cryogenic electron microscopy contrasting agent by binding selectively to encapsulated mRNA without disturbing lipid nanoparticle morphology. Cryo-electron microscopy images identify the mRNA location, revealing that mRNA may exist within solvent-filled cavities or may be substantially lipid associated.

Increasing the strength and bioactivity of collagen scaffolds using customizable arrays of 3D-printed polymer fibers.

Unlabelled: Tendon is a highly aligned connective tissue which transmits force from muscle to bone. Each year, people in the US sustain more than 32 million tendon injuries. To mitigate poor functional outcomes due to scar formation, current surgical techniques rely heavily on autografts.

Tunable, Photoreactive Hydrogel System To Probe Synergies between Mechanical and Biomolecular Cues on Adipose-Derived Mesenchymal Stem Cell Differentiation.

The incorporation of the photoreactive molecule benzophenone into polyacrylamide hydrogels, allowing for orthogonal control over spatial incorporation of biomolecules and selective modulation of matrix stiffness, is described. Adipose-derived mesenchymal stem cells were cultured on matrices whose elastic moduli are tuned to ∼5, ∼14, and ∼37 kPa combined with an immobilized growth factor, bone morphogenic protein 2 (BMP-2), and their lineage differentiation was determined. BMP-2 was observed to have the most pronounced effect at the intermediate stiffness, while the lowest and highest stiffness hydrogels are directed by elasticity alone.

The combined effects of matrix stiffness and growth factor immobilization on the bioactivity and differentiation capabilities of adipose-derived stem cells.

Biomaterial designs are increasingly incorporating multiple instructive signals to induce a desired cell response. However, many approaches do not allow orthogonal manipulation of immobilized growth factor signals and matrix stiffness. Further, few methods support patterning of biomolecular signals across a biomaterial in a spatially-selective manner.

Collagen scaffold arrays for combinatorial screening of biophysical and biochemical regulators of cell behavior.

Arrays of 3D macroporous collagen scaffolds with orthogonal gradations of structural and biomolecular cues are described. Gradient maker technology is applied to create linear biomolecular gradients within microstructurally distinct sections of a single CG scaffold array. The array set up is used to explore cell behaviors including proliferation and regulation of stem cell fate.

Bromelain decreases neutrophil interactions with P-selectin, but not E-selectin, in vitro by proteolytic cleavage of P-selectin glycoprotein ligand-1.

Stem bromelain, a cysteine protease isolated from pineapples, is a natural anti-inflammatory treatment, yet its mechanism of action remains unclear. Curious as to whether bromelain might affect selectin-mediated leukocyte rolling, we studied the ability of bromelain-treated human neutrophils to tether to substrates presenting immobilized P-selectin or E-selectin under shear stress. Bromelain treatment attenuated P-selectin-mediated tethering but had no effect on neutrophil recruitment on E-selectin substrates.