What are the legal implications to safeguard competition between partners of joint venture in the United States for a foreign fund?

I am not completely clear on your question. If you are asking if you can prevent a US joint venture partner from stopping you from taking an intellectual property you gain through the venture and using it in other companies or locations, I think this would be unlikely given how the IP is protected and how it would be covered in the agreement. For other types of biotech investments unrelated to the IP but that you came upon based on your experience with your partner in the US, these restrictions would typically be part of the negotiation of the JV agreement. It would not be unusual for an investor such as yourself, as well as for your partner, to have a provision in the JV agreement that allows each to pursue other investments that do not use the JV's IP or something directly competitive, so you would each be free to pursue other biotech ventures or ideas independently outside of your venture if such a provision is contained in the JV agreement.

I have spent a great deal of time negotiating one aspect of non-compete provisions during the last year, specifically describing limitations on what a venturer can do upon leaving the venture. These typically restrict the former venturer from hiring or soliciting employees of the venture and from opening competing businesses usually within a pre-agreed upon geographic area. That doesn't sound like what you are trying to achieve. Without further information, I can't determine whether the technology in this question is patented, trademarked or otherwise proprietary to the biotech company. If that is the case, you will want to carefully think about what you need and how that impacts the business of the biotech company. It may be possible for you to license technology or work out a sharing arrangement. It is important to have a clear game plan in advance. I would be pleased to assist you in that quest.