In a recent study published in Nature Communications, Zhou et al. reported a sprayable, self-oxygenating hydrogel (HIL@Z/P/H), encapsulating photosynthetic cyanobacteria (PCC 7942), and tumor-targeted nanomedicine (HIL@Z), which could rapidly crosslink at the melanoma resection site, not only effectively inhibited tumor recurrence or metastasis but also aided in wound healing postsurgery.1
Melanoma, a highly aggressive and metastatic cancer, predominantly relies on surgical intervention as its primary treatment modality. Despite surgical resection, the challenge persists in completely eradicating all malignant tissue, especially residual cells along the operative margins, which are particularly prone to triggering local recurrence.2 As has been demonstrated, the hypoxic conditions at the surgical site promote the dissemination and distant metastasis of residual melanoma cells while perpetuating a chronic inflammatory state within the wound. This not only hampers the healing process but also constitutes a profound risk to the patient's survival and diminishes the quality of their postsurgical life.3 To minimize risks and accelerate wound recovery following surgery, radiotherapy, chemotherapy, and immunotherapy therapy are frequently employed as adjunctive treatments.4, 5 However, the therapeutic outcomes of these strategies often fall short of expectations and are accompanied by notable toxic side effects. Hence, the pursuit of efficacious strategies to alleviate the hypoxic microenvironment has emerged as a crucial goal.
Therefore, addressing the fundamental issue of the deteriorative hypoxic microenvironment after surgery that leads to tumor recurrence/metastasis and delayed wound healing, Zhou's group employed nanotechnology to design a therapeutic hydrogel (Figure 1A). Specifically, they noticed PCC 7942, microorganisms that harness a primitive photosynthetic system to produce oxygen in a lasting and controllable manner, making them a promising candidate to explore as an oxygen generator for alleviating hypoxia. Besides, they fabricated HIL@Z, which was composed of hyaluronic acid (HA), indocyanine green (ICG), L-arginine (L-Arg), and zeolite imidazole framework (ZIF-8). Next, they proceeded to encapsulate the PCC 7942 along with HIL@Z in situ at the surgical wound site by spraying a calcium alginate hydrogel. Noteworthy, the porous channels of the hydrogel facilitated nutrient and gas transport (Figure 1B), which can provide an ideal environment for PCC 7942 to support their long-term survival and thereby maintain consistent photosynthetic oxygenation. The photosynthetic oxygenation capability of HIL@Z/P/H did not show significant changes during 15 days of storage, demonstrating excellent stability in oxygenation efficiency (Figure 1C). After obtaining HIL@Z/P/H, Zhou and colleagues proceeded to further validate its func