Injectable Polymer Barrier for Reversible Male Contraception

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Solution Overview

Problem

There is a lack of effective and reversible male contraceptives, leading to unequal burdens on females for unplanned pregnancies and contraceptive management.

Innovation Solution

A method involving the injection of a biocompatible polymer, such as sodium alginate, into the vas deferens with a small gauge needle, forming a temporary barrier that blocks sperm flow, which can be degraded using a calcium chelator like EDTA, providing a reversible form of male birth control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a polymer is injected into the vas deferens to form a contraceptive barrier, then contraceptive effectiveness is improved, but the procedure complexity and invasiveness increase

Engineering Contradiction:

Improvecontraceptive effectivenessVSAvoidprocedure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the physical state parameter of the polymer from solid/high-viscosity to liquid/low-viscosity form for injection, then allows it to gel in situ. This parameter transformation enables delivery through simple needle injection rather than complex surgical implantation, reducing procedure complexity while maintaining contraceptive effectiveness.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a gel-forming polymer as an intermediary substance that can be easily injected but then transforms into a firm barrier. This intermediary approach allows the procedure to use simple injection equipment while achieving the mechanical barrier effect of more complex implants.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If a large gauge needle is used to inject the polymer, then injection capability is improved, but health risks and patient discomfort increase

Engineering Contradiction:

Improveinjection capabilityVSAvoidhealth risks

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent transforms the polymer into a low-viscosity liquid state that can flow through small bore needles (25-30 gauge). This parameter change in the polymer's physical state enables the use of fine-gauge needles, eliminating the need for large needles while maintaining successful injection capability.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If the polymer is made reversible for future fertility restoration, then adaptability is improved, but the mechanism complexity increases

Engineering Contradiction:

ImprovereversibilityVSAvoidmechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical or surgical reversal mechanisms with a simple chemical solution approach. A calcium chelator solution is injected to chemically dissolve the calcium-alginate gel barrier, providing reversibility without requiring complex mechanical removal or surgical intervention.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Object-affected harmful factors

If a minimally invasive injection method is used, then patient comfort and safety are improved, but the ability to form an effective barrier may be compromised

Engineering Contradiction:

Improvepatient safetyVSAvoidbarrier effectiveness

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent exploits the phase transition of the polymer from liquid injection form to gel barrier form in situ. This phase change occurs after injection, allowing the minimally invasive delivery method to still produce a firm, effective mechanical barrier that reliably blocks sperm transport.

Inventive Principle:

Principle #36Phase transitions

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method offers a minimally invasive, reversible, and effective male contraceptive that blocks sperm flow for at least one year without requiring stitches and reduces health risks associated with larger needles, while being cost-effective and hormone-free.

Implementation Method 1

the polymer solution forms a polymer gel in the vas deferens that blocks sperm transport

Methodology Applied

Scientific EffectGel formation: Gel

Implementation Method 2

injecting a calcium chelator in the vas deferens to degrade the polymer barrier

Methodology Applied

Scientific EffectChelation:

Data Source

PatentUS12496270B2Methods for reversible male birth control

Publication Date: 2025.12.16 MTOLOGY INNOVATIONS LLC

AI summary

Contraceptives and methods for reversible male birth control are disclosed herein. One method includes providing a polymer including a viscosity and reducing the viscosity of the polymer to create a polymer solution. The method further includes injecting the polymer solution into the vas deferens of a male subject while the viscosity of the polymer is reduced. The polymer solution forms a polymer barrier in the vas deferens to physically block the outflow of sperm in the vas deferens subsequent to injection.