(T1130-03-17) A Novel Simulated Plant Based IVG Cervical Mucus Formulation for Sperm Functional Assays with Optimized Spinnbarkeit and Viscosity

Purpose: Challenges associated with human cervical mucus include, limited availability and variability, hence a simulated cervical mucus provides an attractive alternative. This study simulated cervical mucus formulation using IVG seed powder cross-linked with sodium borate and dried porcine gastric mucin, prepared in a pH 7.4, 0.1M phosphate buffer.

Methods: Pre-formulated simulated cervical mucus formulations were developed using an extended hydration process. Formulation optimization using artificial neural network (ANN) modeling, generated 20 variable formulations. These formulations were designed using three independent (input) variables: IVG concentration, mucin-to-hyaluronic acid ratio, and xanthan gum concentration. To investigate the response pattern and identify the best set of variables for optimizing the selected responses, the experimental design for the current study was developed using a three-factor central composite design (CCD) (Table 2). With star points, the CCD combines the vertices of a hypercube whose coordinates are determined by a 2n factorial design. The nonlinear response surface's curvature is estimated using the star points.

Results: The resulting dependent (output) variables included spinnbarkeit, viscosity, and percentage sperm motility. To validate and compare results, other machine learning models were used alongside the ANN and tested against experimental observations to obtain one optimized formulation. Additional parameters such as appearance, consistency, pH, and electrical conductivity were also evaluated to ensure the formulations closely mimicked human cervical mucus. The optimized synthetic cervical mucus formulation exhibited an average spinnbarkeit of 13.5 ± 0.4 cm, a viscosity of 8,660 cP, and a sperm motility percentage of 25%. It had a creamy-white appearance, attributed to the natural color of IVG, with a moderate to thick consistency, a pH of 7.40 ± 0.01, and electrical conductivity of 10.61 ± 0.12 mS/cm.

Conclusion: The simulated cervical mucus formulated with IVG outperforms the synthetic cervical mucus developed with guar gum in multiple aspects. Unlike the guar gum-based formulation, IVG-based mucus contains essential biomolecules naturally present in human cervical mucus, such as proteins, fats, amino acids, and vitamins, enhancing its biological relevance. In terms of viscosity, the IVG formulation exhibited a significantly higher viscosity (8,660 cP) compared to the guar gum-based synthetic mucus (3,960 cP). Similarly, it demonstrated superior spinnbarkeit, with a stretchability of 13.5 ± 0.4 cm, whereas the guar gum-based formulation had a much lower spinnbarkeit of 2.43 ± 0.06 cm, which is rated at a minimal stretchability score of 1. For sperm motility, the IVG-based mucus further outperformed its counterpart, achieving a sperm motility rate of 25%, compared to 15% in the guar gum formulation.

References: 1. C. Lee, Y. Wang, S. Shin, Y. Chien, Effects of chelating agents on the rheological property of cervical mucus, Contraception. 65 (2002) 435–40. https://linkinghub.elsevier.com/retrieve/pii/S0010782402003001
2. B. Burruano, R. Schnaare, D. Malamud, Synthetic cervical mucus formulation. Contraception. 66 (2002) 137–40. https://linkinghub.elsevier.com/retrieve/pii/S0010782402003360

Acknowledgements: This work is supported through Grand Challenges Africa GCA-R13-01 obtained by Dr. Margaret Ilomuanya. Grand Challenges Africa (GC Africa is an initiative of the Science for Africa Foundation, a pan-African, non-profit, and public charity organization that supports, strengthens, and promotes science and innovation in Africa. The views expressed herein are those of the authors and not necessarily those of the SFA Foundation and her partners.