Release of molecules from nanocarriers

Abstract

Release of drug or vaccine molecules from macro-, micro-, and nano-sized carriers is usually considered to be limited by diffusion and/or carrier dissolution and/or erosion. The corresponding experimentally observed kinetics...

Diffusion-Limited Release of Molecules from Nanocarriers with Appreciable Energetic Heterogeneity

“…Second, the logarithmic features are predicted by using the approximations, which are physically justified, and accordingly, these features cannot be viewed just as a purely mathematical trick based on axiomatically introduced fitting functions. Of note, one can add that eqs 22) and ( 23) are similar to those used earlier to describe desorption from heterogeneous surfaces 33 and the kinetically limited release of molecules from nanocarriers, 6 and the corresponding desorption kinetics are long known to be logarithmic. 33 Thus, such kinetics can be observed irrespective of whether the release is kinetically or diffusionally limited.…”

“…The model is, however, general and allows one to employ an arbitrary E distribution in order to calculate the concentration-dependent diffusion coefficient and the corresponding release kinetics. Among the E distributions used earlier, the author can mention, e.g., the Gaussian and log-normal distributions and linearly increasing or decreasing distributions …”

“…Regarding the experiments, the α values obtained are often in the range of 0.45–0.85 (reviewed in refs ,). The lower values of α are sometimes reported as well, as one can see, e.g., in recent studies, − focused primarily on nanocarriers with a size of ∼100 nm.…”

“…Release of molecules from carriers is of interest in the context of basic science and from the perspective of applications in various fields ranging from medicine (e.g., drug and vaccine delivery by macroscopic pellets and nanocarriers) to energetics (e.g., hydrogen storage and sensors). This process can be limited by the diffusion of atoms or molecules in carriers or kinetically limited by processes at and/or near the interface between a carrier and the external medium . Other mechanisms of release include the dissolution and/or disintegration of carriers .…”

“…This process can be limited by the diffusion of atoms or molecules in carriers 5 or kinetically limited by processes at and/or near the interface between a carrier and the external medium. 6 Other mechanisms of release include the dissolution and/or disintegration of carriers. 7 The specifics of the release kinetics depend on whether the carrier structure is homogeneous or heterogeneous.…”