The host response to biomaterials is a critical determinant of their success or failure in tissue-repair applications. Macrophages are among the first responders in the host response to biomaterials and have been shown to be predictors of downstream tissue remodeling events. Biomaterials composed of mammalian extracellular matrix (ECM) in particular have been shown to promote distinctive and constructive remodeling outcomes when compared to their synthetic counterparts, a property that has been largely attributed to their ability to modulate the host macrophage response. ECM bioscaffolds are prepared by decellularizing source tissues such as dermis and small intestinal submucosa. The differential ability of such scaffolds to influence macrophage behavior has not been determined. The present study determines the effects of ECM bioscaffolds derived from eight different source tissues upon macrophage surface marker expression, protein content, phagocytic capability, metabolism, and antimicrobial activity. The results show that macrophages exposed to small intestinal submucosa (SIS), urinary bladder matrix (UBM), brain ECM (bECM), esophageal ECM (eECM), and colonic ECM (coECM) express a predominant M2-like macrophage phenotype, which is pro-remodeling and anti-inflammatory (iNOS-/Fizz1+/CD206+). In contrast, macrophage exposure to dermal ECM resulted in a predominant M1-like, pro-inflammatory phenotype (iNOS+/Fizz1-/CD206-), whereas liver ECM (LECM) and skeletal muscle ECM (mECM) did not significantly change the expression of these markers. All solubilized ECM bioscaffold treatments resulted in an increased macrophage antimicrobial activity, but no differences were evident in macrophage phagocytic capabilities, and macrophage metabolism was decreased following exposure to UBM, bECM, mECM, coECM, and dECM. The present work could have important implications when considering the macrophage response following ECM implantation for site-appropriate tissue remodeling. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 138-147, 2017.

Cavity-mediated light–matter coupling can dramatically alter opto-electronic and physico-chemical properties of a molecule. Ab initio theoretical predictions of these systems need to combine non-perturbative, many-body electronic structure theory-based methods with cavity quantum electrodynamics and theories of open-quantum systems. Here, we generalize quantum-electrodynamical density functional theory to account for dissipative dynamics of the cavity and describe coupled cavity–single molecule interactions in the weak-to-strong-coupling regimes. Specifically, to establish this generalized technique, we study excited-state dynamics and spectral responses of benzene and toluene under weak-to-strong light–matter coupling. By tuning the coupling, we achieve cavity-mediated energy transfer between electronically excited states. This generalized ab initio quantum-electrodynamical density functional theory treatment can be naturally extended to describe cavity-mediated interactions in arbitrary electromagnetic environments, accessing correlated light–matter observables and thereby closing the gap between electronic structure theory, quantum optics, and nanophotonics.

Mechanical forces affect a myriad of processes, from bone growth to material fracture to touch-responsive robotics. While nano- to micro-Newton forces are prevalent at the microscopic scale, few methods have the nanoscopic size and signal stability to measure them in vivo or in situ. Here, we develop an optical force-sensing platform based on sub-25 nm NaYF nanoparticles (NPs) doped with Yb, Er, and Mn. The lanthanides Yb and Er enable both photoluminescence and upconversion, while the energetically coupled d-metal Mn adds force tunability through its crystal field sensitivity. Using a diamond anvil cell to exert up to 3.5 GPa pressure or ∼10 μN force per particle, we track stress-induced spectral responses. The red (660 nm) to green (520, 540 nm) emission ratio varies linearly with pressure, yielding an observed color change from orange to red for α-NaYF and from yellow-green to green for d-metal optimized β-NaYF when illuminated in the near infrared. Consistent readouts are recorded over multiple pressure cycles and hours of illumination. With the nanoscopic size, a dynamic range of 100 nN to 10 μN, and photostability, these nanoparticles lay the foundation for visualizing dynamic mechanical processes, such as stress propagation in materials and force signaling in organisms.

While the emerging field of vibrational polariton chemistry has the potential to overcome traditional limitations of synthetic chemistry, the underlying mechanism is not yet well understood. Here, we explore how the dynamics of unimolecular dissociation reactions that are rate-limited by intramolecular vibrational energy redistribution (IVR) can be modified inside an infrared optical cavity. We study a classical model of a bent triatomic molecule, where the two outer atoms are bound by anharmonic Morse potentials to the center atom coupled to a harmonic bending mode. We show that an optical cavity resonantly coupled to particular anharmonic vibrational modes can interfere with IVR and alter unimolecular dissociation reaction rates when the cavity mode acts as a reservoir for vibrational energy. These results lay the foundation for further theoretical work toward understanding the intriguing experimental results of vibrational polaritonic chemistry within the context of IVR.