Silicones preventing nutrition of hair? (Chemistry and common sense. Your opinion?)
 

I have a question for all of the experienced and knowledgeable curlies out there:

The dilemma: Consider the idea of using Hello Hydration conditioner, but not wanting to use a sulfate-y cleanser. Hello Hydration contains an amine-functionalized silicone, a silicone that is chemically incapable of building up upon itself (though it does still coat the hair temporarily). No build-up is great, but I wonder if it still might hurt the nutrition of my hair.

Here's why: Silicons, when used, prevent the loss of moisture, i.e. water exiting the hair shaft in a aerosol state.

The Question: Does it stand to reason that silicons also prevent substances from entering the hair shaft? Things like fortifying oils? Or the ingredients of my moisturizing leave-in conditioner? I need those things!

Curlies like myself just want to make sure that our hair will still be able to get what it needs. Will silicons hurt that?