The minimum investment amount of either $500,000 or $1,000,000 must be your own funds or from a gift or loan not secured by the investment.
This concept is in a bill pending in Congress that would create EB-6 visas but has not passed into law as of this writing.
Under existing EB-5 law, a person can obtain their investment capital from a variety of sources, such as a gift, inheritance, wages, their life savings, cashing in stocks/bonds, selling real estate or other property (such as jewelry or works of art/antiques, etc..). In some cases a person might obtain investment capital from a "loan" but such a "loan" can only be secured by the alien investor's assets (or signature--good luck with that!). Any loan CANNOT be secured by the assets purchased for or by the commercial enterprise receiving EB-5 funds. It is not very feasible at the present time.
That being said, there is nothing stopping Angel Investors from joining with EB-5 investors. In fact, the Congressional Intent for the creation of the Regional Centers was pooling investments and specifically encourages "increased domestic capital investments". However, non-EB-5 Investors have no statutorily prescribed minimum or maximum amounts, it merely has to be lawful funds. Additionally, the jobs created by the non-EB-5 partners can ALL be counted by their alien partners seeking EB-5 visas. So, for projects that have lower job creation potential, non-EB-5 Angels make them viable for Regional Centers to coordinate. The original investor visas were truly meant for entrepreneurs. Ever since Regional Centers were allowed under the law, the vast majority of EB-5 investors have themselves actually been "Angel Investors" funding growth in the United States as long as such projects could meet the job creation requirements.
It's a definite maybe!