Gas‐Generating Nanoplatforms: Material Chemistry, Multifunctionality, and Gas Therapy

Abstract

The fast advances of theranostic nanomedicine enable the rational design and construction of diverse functional nanoplatforms for versatile biomedical applications, among which gas-generating nanoplatforms (GGNs) have emerged very recently as unique theranostic nanoplatforms for broad gas therapies. Here, the recent developments of the rational design and chemical construction of versatile GGNs for efficient gas therapies by either exogenous physical triggers or endogenous disease-environment responsiveness are reviewed. These gases involve some therapeutic gases that can directly change disease status, such as oxygen (O ), nitric oxide (NO), carbon monoxide (CO), hydrogen (H ), hydrogen sulfide (H S) and sulfur dioxide (SO ), and other gases such as carbon dioxide (CO ), dl-menthol (DLM), and gaseous perfluorocarbon (PFC) for supplementary assistance of the theranostic process. Abundant nanocarriers have been adopted for gas delivery into lesions, including poly(d,l-lactic-co-glycolic acid), micelles, silica/mesoporous silica, organosilica, MnO , graphene, Bi Se , upconversion nanoparticles, CaCO , etc. Especially, these GGNs have been successfully developed for versatile biomedical applications, including diagnostic imaging and therapeutic use. The biosafety issue, challenges faced, and future developments on the rational construction of GGNs are also discussed for further promotion of their clinical translation to benefit patients.

Emerging Delivery Strategies of Carbon Monoxide for Therapeutic Applications: from CO Gas to CO Releasing Nanomaterials

“…Then, the produced ROS could effectively oxidize LA and eventually cause NO generation. Collectively, these studies offer enlightening strategies to extend the application scope of stimuli‐responsive CORMs and further develop various stimuli‐responsive CO releasing nanoplatforms for future CO therapy …”

“…Compared with external stimuli‐induced CO release, the release of CO triggered by specific pathologic microenvironment (such as H 2 O 2, glutathione, cysteine, pH and enzyme) is not limited by the penetration depth and thus is more advantageous to tissue‐specific CO therapy …”

“…Another notable obstacle for the therapeutic application of CORMs is the difficulty of controlling the amount of CO release to biological targets . Fortunately, the utility of nanomaterials can not only achieve the targeted delivery of CORMs, but also modulate the responsiveness of CORMs to a wide variety of stimuli, and ultimately improve the spatio‐temporal controllability of CO release.…”

“…Besides, due to the advantages of facile manipulation, high tissue penetrating depth and energy focusing, other exogenous stimuli, like X‐ray, ultrasound and microwave, have also been widely integrated with functionalized nanomaterials for remote‐controlled gas release and biomedical therapeutic application . For example, our group previously reported a multifunctional X‐ray controlled ONOO − generation platform containing scintillating nanoparticles (SCNPs) and UV‐responsive NO donors Roussin's black salt (RBS) .…”

Multi-mode biodegradable tumour-microenvironment sensitive nanoparticles for targeted breast cancer imaging

“…Ideal ultrasound contrast agents should generally exhibit an optimal size for transport through the tissue vascular space, an adequate duration of acoustic effect, good targeting and biocompatibility, and easy excretion from the body [8,9]. The concept of "gas-generating nanoparticles" was proposed in prior research, and such nanoparticles have the potential for use in ultrasound contrast imaging [10][11][12]. These gas-generating nanoparticles are superior to the current gas-filled microbubbles in performance, and the continuously generated gas enables intense ultrasound imaging.…”