Zeolites for storage and delivery of nitric oxide in human physiology

Metal–Organic Frameworks in Biomedicine

“…As in the NONOate case the release of NO is triggered by exposure to moisture (or any other nucleophile of sufficient strength). NO-releasing zeolites show the expected biological activity. , Wheatley et al , demonstrated antithrombosis activity on human platelet-rich plasma and Mowbray and co-workers have completed studies on human skin that show no significant inflammation on application of NO-releasing zeolites, in contrast to chemically produced NO (from acidified nitrite creams), which is a competitor to gas storage materials for topical delivery . NO-loaded zeolites also showed excellent bifunctional antibacterial activity, consistent with the expected behavior of NO …”

New generation of nitric oxide-releasing porous materials: Assessment of their potential to regulate biological functions

“…So far, studies using these new donors concerning their biocompatibility, stability and control of biological processes with the NO released are still poorly explored. Only few papers, using MOFs and zeolites based materials, demonstrated that NO released from those materials is able to inhibit platelet aggregation [7,18], to relax smooth muscle of blood vessels [9] and stimulate the wound healing process [19]. However, no actual demonstration of control of the biological systems was provided, namely by establishing a relationship between the response extension/intensity and the amount of NO released to the system.…”

Development of Polycaprolactone–Zeolite Nanoporous Composite Films for Topical Therapeutic Release of Different Gasotransmitters

“…Examples of such materials include zeolites, titanosilicates, clays, and metal–organic frameworks, with storing capacities ranging from ca. 1 to 7 mmol of gas per g of material, covering a wide range of therapeutic needs. , Zeolites are particularly interesting carriers due to their easy commercial access, chemical stability, and biocompatibility features, being used for decades in drug delivery. , Zeolite A, a three-dimensional nanoporous crystalline aluminosilicate, is within the few porous materials that demonstrate the ability to adsorb therapeutic amounts of either NO or H 2 S. ,, Moreover, this zeolite offers a great advantage to be easily modified by ion exchange, being possible to achieve different release profiles by tailoring the type and number of metal cations present in the framework. , However, due to their high affinity to water, zeolites present a quick NO/H 2 S release when in contact with biological solutions and the ion-exchanged configurations are not stable enough in aqueous media, releasing the metals along with the gas in the therapeutic tissues, compromising their efficient delivery and inducing cell toxicity. ,, …”

“…21,22 Zeolite A, a three-dimensional nanoporous crystalline aluminosilicate, is within the few porous materials that demonstrate the ability to adsorb therapeutic amounts of either NO or H 2 S. 19,23,24 Moreover, this zeolite offers a great advantage to be easily modified by ion exchange, being possible to achieve different release profiles by tailoring the type and number of metal cations present in the framework. 23,25 However, due to their high affinity to water, zeolites present a quick NO/H 2 S release when in contact with biological solutions and the ionexchanged configurations are not stable enough in aqueous media, releasing the metals along with the gas in the therapeutic tissues, compromising their efficient delivery and inducing cell toxicity. 20,23,26 Recent efforts have been focused on the incorporation of these new donors into polymeric matrices in an attempt to provide practical clinical solutions (e.g., device coatings, wound dressings) and to potentiate the donor's features.…”