Final answer:
Wound healing may need to be halted due to elevated MMPs and host proteases when these factors interrupt the normal repair process or contribute to tumor progression. Targeted therapies using complex drug delivery systems have been developed to harness elevated MMP levels for selective tumor treatment.
Step-by-step explanation:
The role of MMPs and other host proteases is critical in the wound healing process. Elevated levels of MMPs, especially MMP2 and MMP9, are often associated with the invasion, progression, and metastasis of human tumors. Such elevated protease activity can disrupt the normal process of wound healing, leading to impaired tissue repair. In cases of cancer, targeting therapies toward these proteases has been shown to increase the selectivity of drug delivery to tumor sites and improve treatment efficacy. By utilizing multifunctional complex drug delivery systems, such as those developed by Zhu, drugs can be delivered specifically to the tumor cells, leveraging the up-regulated levels of MMP2 in the tumor microenvironment.
Moreover, inflammation, which is a classic body response to injury, can be negatively affected by stress, as shown by Glaser et al., suggesting that managing stress levels can indirectly influence levels of MMPs and the rate of wound healing. Strategies for wound management could, therefore, include the inhibition of MMPs when excessive levels interfere with tissue regeneration or when aiming to halt the spread of malignant cells.