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. 2017 Oct 26;12(10):e0186268.
doi: 10.1371/journal.pone.0186268. eCollection 2017.

Thermosensitive hydrogels deliver bioactive protein to the vaginal wall

Meadow M Good  1 , T Ignacio Montoya  1 , Haolin Shi  1 , Jun Zhou  2 , YiHui Huang  2 , Liping Tang  2 , Jesus F Acevedo  1 , R Ann Word  1
Affiliations

Thermosensitive hydrogels deliver bioactive protein to the vaginal wall

Meadow M Good et al. PLoS One. .

Abstract

The pathophysiology and natural history of pelvic organ prolapse (POP) are poorly understood. Consequently, our approaches to treatment of POP are limited. Alterations in the extracellular matrix components of pelvic support ligaments and vaginal tissue, including collagen and elastin, have been associated with the development of POP in animals and women. Prior studies have shown the protease MMP-9, a key player of ECM degradation, is upregulated in vaginal tissues from both mice and women with POP. On the other hand, fibulin-5, an elastogenic organizer, has been found to inhibit MMP-9 in the vaginal wall. Hence, we hypothesized that prolonged release of fibulin-5 may delay progression of POP. To test the hypothesis, oligo (ethylene glycol)-based thermosensitive hydrogels were fabricated, characterized and then used to deliver fibulin-5 to the vaginal wall and inhibit MMP-9 activity. The results indicate that hydrogels are cell and tissue compatible. The hydrogels also prolong the ½ life of fibulin-5 in cultured vaginal fibroblasts and in the vaginal wall in vivo. Finally, fibulin-5-containing hydrogels resulted in incorporation of fibulin-5 into the vaginal matrix and inhibition of MMP-9 for several weeks after injection. These results support the idea of fibulin-5 releasing hydrogel being developed as a new treatment for POP.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Thermosensitive property of the polymer solution.
A. Transmittance of the polymer aqueous solution (0.5 wt%) as a function of temperature. B. Thermally-induced gelation of the HG aqueous solution (25 wt%).
Fig 2
Fig 2. In vitro cell compatibility and in vivo tissue compatibility of HG was assessed.
(A) HG was incubated with DMEM media for different periods of time (1, 3, 5 and 7 days) to generate conditioned media. The cell compatibility of the conditioned media was then evaluated using 3T3 fibroblasts and MTT assay. (B) Balb/c mice were subcutaneously implanted with HG or saline as the control. After implantation for 7 days, the animals were sacrificed and the implant-surrounding tissues were recovered for histological analyses. H&E stain and implant-associated cell numbers support that HG implant exerted minimal tissue response similar to saline control.
Fig 3
Fig 3. Release kinetics from PEG hydrogels.
Upper panels are representative images of BSA-NIR fluorescence intensities at intravaginal injections as a function of time. Release kinetics from hydrogels (BSA-HG) are compared with that of BSA without HG. The percent BSA released was calculated based on the following formula. Release % = 100X [(Fluorescent intensity at time 0)–(fluorescent intensity at time T)] / (Fluorescent intensity at time 0). Note that release rates are delayed with HG compared with BSA alone. *P < 0.05.
Fig 4
Fig 4
Effect of HG ± fibulin-5 on MMP-9 activity in vaginal stromal cells from WT (A) or Fbln5-/- (B) mice. HG, hydrogel; Fib-55, recombinant fibulin-5 5 μg/ml; Fib-510, recombinant fibulin-5 10 μg/ml. -Ctl, vaginal tissues from MMP-9 KO mice; +Ctl, vaginal tissues from Fbln5-/- mice.
Fig 5
Fig 5. Effect of HG ± fibulin-5 on vaginal MMP-9 and MMP-2 in Fbln5 KO mice treated for 7 d.
A. Gelatin zymography with protein extracts (10 μg/lane) from adult Fbln5-/- mice injected with hydrogel alone (HG), HG incorporated with fibulin-5 (5 ug/ml), or fibulin-5 alone x 7 d. Mmp9 KO was used as a neg ctl. B. Cumulative results of 34 mice treated with HG ± various doses of fibulin-5 x 7 d. *P < 0.05 compared with HG alone, ANOVA.
Fig 6
Fig 6. Recovery of fibulin-5 in vaginal tissues from Fbln5-/- mice injected with hydrogel (HG) ± recombinant fibulin-5 (FN5).
Urea extracts (10 μg/lane, A) revealed incorporation of fibulin-5 in matrix fractions of KO animals 7 d after injection with HG+FN-5 (equivalent to that in WT animals). WT urea extracts were used as the + control in the soluble fractions (B).
Fig 7
Fig 7. Long-term effects of HG ± fibulin-5 on vaginal MMP-9 in Fbln5 KO mice treated for 14–28 d.
A. Cumulative results of MMP-9 activity in vaginal tissues from 38 mice treated with HG ± fibulin-5 (10 μg/ml) for 2–4 weeks. *P < 0.05 compared with HG alone, ANOVA. B. Immunoblot analysis of urea-extracted protein from vaginal tissues of Fbln5-/- mice treated with HG or HG + FBLN5 (10 μg/ml) x 2 weeks. The left blot was incubated with anti- His Tag antibody whereas the right blot was incubated with anti-fibulin-5. Positive controls on each blot are recombinant fibulin-5 (rFBLN5, 200 ng). Bl, blank.
Fig 8
Fig 8. Trichrome-stained sections of the vaginal wall of Fbln5-/- mice treated with HG (A) or HG+fibulin-5 (10 μg/ml).
Note increased thickness of epithelial and stromal layers in animals treated with fibulin-5. Bar = 20 μm.
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References

    1. Jelovsek JE, Maher C, Barber MD. Pelvic organ prolapse. Lancet. 2007;369(9566):1027–38. doi: 10.1016/S0140-6736(07)60462-0 . - DOI - PubMed
    1. Olsen AL, Smith VJ, Bergstrom JO, Colling JC, Clark AL. Epidemiology of surgically managed pelvic organ prolapse and urinary incontinence. Obstetrics & Gynecology. 1997;89(4):501–6. - PubMed
    1. Gyhagen M, Bullarbo M, Nielsen TF, Milsom I. Prevalence and risk factors for pelvic organ prolapse 20 years after childbirth: a national cohort study in singleton primiparae after vaginal or caesarean delivery. BJOG. 2013;120(2):152–60. doi: 10.1111/1471-0528.12020 . - DOI - PubMed
    1. Clark AL, Gregory T, Smith VJ, Edwards R. Epidemiologic evaluation of reoperation for surgically treated pelvic organ prolapse and urinary incontinence. Am J Obstet Gynecol. 2003;189(5):1261–7. . - PubMed
    1. Word RA, Pathi S, Schaffer JI. Pathophysiology of pelvic organ prolapse. Obstet Gynecol Clin North Am. 2009;36(3):521–39. doi: 10.1016/j.ogc.2009.09.001 . - DOI - PubMed

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