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Quantification of intraoperative administration of mitomycin-C in filtering surgery with surgical sponge material
J M Larrosa1, V Polo, I Pinilla
1Department of Ophthalmology, Miguel Servet Hospital, Zaragoza, Spain.
Purpose:
To determine the absorption and release of mitomycin-C 0.4 and 0.2 mg/mL from sponge-like specimens of Spongostan film (Ferrosan, Copenhagen, Denmark) and the scleral and conjunctival impregnation in an experimental model of filtering surgery.
Methods:
The maximum amount of mitomycin per volume unit that Spongostan is able to absorb was determined physically as the difference between dry weight and soaked weight. Mitomycin-C activity in known volumes of Spongostan after mitomycin-C release in vitro also was determined at 0, 1, 10, and 30 seconds and 1, 3, 5, 10, 15, and 30 minutes. Antibiotic activity of the specimens was evaluated by means of bioassay. Millimeters of inhibition of bacterial growth were related to microg of mitomycin activity according to a reference curve obtained from known amounts of mitomycin-C. Finally, 10 eyes of 10 rabbits underwent filtering surgery with intraoperative application of mitomycin by means of the Spongostan film. The Spongostan implants then were removed and tested for mitomycin activity. Scleral and conjunctival specimens were obtained for bioassay.
Results:
The maximum capacity of 25 mm2 x 0.5 mm thick Spongostan films saturated in 0.4 and 0.2 mg/mL solutions of mitomycin-C were 8.49 microg and 4.23 microg, respectively. Biologic activity (bioassay determination) was 8.24 microg and 4.19 microg of mitomycin-C, respectively. In vitro release of mitomycin was gradual until 30 minutes. In vivo mitomycin release from Spongostan after 5 minutes was 6.91 microg. Impregnation with the antimitotic was better in conjunctiva than sclera.
Conclusion:
Bioassay permits quantification of mitomycin-C activity. The release from sponge specimens is gradual, and impregnation was better in conjunctiva than sclera.
Insights
Spongostan film effectively absorbs and gradually releases mitomycin-C, showing better impregnation in conjunctiva than sclera during experimental filtering surgery. This study quantifies mitomycin-C activity using bioassay, confirming its gradual release profile.
Area of Science:
- Ophthalmology
- Surgical Innovation
- Pharmacology
Background:
- Mitomycin-C is an antimetabolite used in ophthalmic surgery.
- Spongostan film is a potential delivery vehicle for mitomycin-C.
- Understanding drug release and tissue impregnation is crucial for optimizing surgical outcomes.
Purpose of the Study:
- To quantify mitomycin-C absorption and release from Spongostan film.
- To evaluate scleral and conjunctival impregnation with mitomycin-C.
- To assess the efficacy of Spongostan film in an experimental filtering surgery model.
Main Methods:
- Determined Spongostan film's maximum mitomycin-C absorption capacity.
- Assessed in vitro and in vivo mitomycin-C release kinetics using bioassay.
- Evaluated mitomycin-C impregnation in rabbit sclera and conjunctiva post-surgery.
Main Results:
- Spongostan films demonstrated significant mitomycin-C absorption (up to 8.49 µg).
- Bioassay confirmed high biological activity of absorbed mitomycin-C.
- Gradual in vitro and in vivo release observed; conjunctival impregnation superior to scleral.
Conclusions:
- Bioassay is a reliable method for quantifying mitomycin-C activity.
- Spongostan film provides gradual mitomycin-C release.
- Enhanced conjunctival impregnation suggests potential benefits in filtering surgery.