A Perspective on the Topical Delivery of Macromolecules

[...]many of these studies have been shown to be misleading as a result of inappropriate experimental design or a lack of contextualization of this limitation in the study conclusions. Tritiated HA was detected in the dermis just below the epidermis, and the authors took many steps to eliminate artifacts to ensure the observations were real and valid. Since publication in 1999, the group did not report further findings on HA. [...]there are studies that show latex proteins were able to penetrate excised human skin, and that exposure induced an IgG1 response in vivo (13). Interestingly, aptamers offer significant conformational plasticity and flexibility. [...]their structure can be modified without the loss of significant activity (17, 18).