Are there any implants that don’t have a silicone shell?

There are no implants without a silicone shell.   Fat transfer results in loss of 50-70% of the fat volume that is grafted within 6 months.  Dying fat leaves behind micro calcifications.  Those microcalifications will be confused with micrcalcifications associated with cancers for the rest of your life that will either result in a missed cancer diagnosis or overly aggressive biopsy forever.  Either way the transfer of fat is all one of the most dangerous procedures in plastic surgery and transfer to the breast is controversial.

You might want to consider fat grafting to your breasts. You will need to have donor fat available. With each transfer, you can expect up to one cup increase in size. You might want to meet with a board certified plastic surgeon and discuss your options.

Unfortunately, you have not provided photographs or told us your bra size.  However, an alternative to consider, since there are not any implants without silicone shells, is a breast lift using The Bellesoma Method.  Excess skin is used to make an internal cone analogous to a breast implant, which reshapes your breast tissue creating upper pole fullness without implants, elevates them higher on the chest wall and more medial to increase your cleavage.  Vertical scars are avoided, nipple sensation (in 95%) and the ability to breast feed are maintained.  Later, fat transfers can be performed if additional volume is desired.  Best Wishes,Gary Horndeski, M.D.