The success of the chronic abscess elimination process by NO-np stimulation possibly depends on cytokines and growth factors involved in a complex integration of signals that coordinate cellular processes. For instance, the presence of high levels of pro-inflammatory IL-12 might be related to its anti-angiogenic activity, which can block the formation of new blood vessels, therefore, preventing bacterial dissemination to other organs or tissues. This is accomplished by increasing production of IFN-c, which in turn inhibits endothelial cell motility and vascularization. In this regard, tissue sections stained for CD34, a marker for blood vessel formation, demonstrated that NO-np reduces angiogenesis in MRSA abscesses. In fact, the downregulation of IL-10, which can antagonize IFN-c effects, suggest that NO-np might also impede MRSA dissemination within phagocytes. Additionally, other pro-inflammatory cytokines/chemokines, particularly TNF-a, IL-1 b, and MCP-1 were up-regulated by NO-np. Sustained expression of these proinflammatory effector molecules permits a prolonged presence of neutrophils, macrophages, lymphocytes, and mast cells in the chronic abscess contributing to an effective inflammatory response and bacterial clearance. Escin-IB Nitric oxide activates latent TGF-b, which is believed to regulate collagen deposition by fibroblasts. Furthermore, elevated levels of IFN-c, TNF-a and IL1-b have been shown to directly increase the levels TGF-b. In summary, application of NO as topical agents has been used with success in augmenting wound healing and reducing wound bacterial burden. The presented data show that NO-np have both antimicrobial and wound-healing properties. beta-Carotene Overall, the presented results show that the topical or intradermal application of NO-np is highly effective against subcutaneous MRSA abscesses in a murine model. Conceivably, this technology might be used as a potential therapy prior to or in addition to surgical drainage of bacterial abscesses. It is further possible that the NO-np could be useful in the treatment of deep abscesses via injection into tissues such as the lung or liver. Interestingly, the NO-np appear to significantly stimulate the immune system.