Dear Helen Kas, among a number of water soluble polymers there are some compounds permitting medical application. For example, mark polyvinyl acetate and its derivatives are worthy of mark (see, please, a review attached).    

 Hi Helen 

I published an overview of: Biomaterials in Dentistry and Medicine. In: Biomaterials Developments and Applications, H. Bourg and A. Lisle (Editors), Book Series: Advances in Biology and Medicine, Nova Science Publishers, pp. 231-289. ISBN: 978-1-60876-476-1.

If you have a look at the list of resorbable polymers listed in Table 8 on page 72 this will give you a reasonable idea of the types of materials applied.  

https://www.researchgate.net/publication/257957723_Biomaterials_in_Dentistry_and_Medicine._In_Biomaterials_Developments_and_Applications_H._Bourg_and_A._Lisle_%28Editors%29_Book_Series_Advances_in_Biology_and_Medicine_Nova_Science_Publishers_pp._231-289._ISBN_978-1-60876-476-1#full-text

I'd also recommend:

- Buddy Ratner's Book on Biomaterials Science if you want an overview of the area this is a superb book and although now in its 3rd Edition I still like/prefer the 1st Edition if you can find a copy

More specific overview:

- Zheng Zhang, Ophir Ortiz, Ritu Goyal, Joachim Kohn Chapter 23 – Biodegradable Polymers Principles of Tissue Engineering (Fourth Edition) Edited by:Robert Lanza, Robert Langer and Joseph P. Vacanti (2014)

Chapter Biomaterials in Dentistry and Medicine. In: Biomaterials Dev...

Your question is general. You will find lot of reviews and books on the topic also on scifinder/scopus or simply on google. we work on Poly(N-isopropylacrylamide)s which are also interesting class of stimuli that is thermoresponsive polymers. It is water soluble and frequently used to prepare drug delivery systems.

Thank you for all answers and attachment