Biologically acceptable surgical barrier materials are comprised of a polyelectrolytic complex of chitosan and sodium alginate. The chitosan is deacetylated in an amount between about 40 to about 60% and has a molecular weight (Mw) between 50,000 and 375,000 g/mol. The barrier materials may be formed by mixing a two-component material system whereby one component comprises the chitosan and a second component comprises the sodium alginate and directing such a mixture (e.g., via air-assisted spray nozzle) toward a surgical site in need of the material. A polyelectrolytic complex of the chitosan and sodium alginate will thereby form in situ. Suitable ionic cross-linkers may be provided in the individual components, e.g., calcium chloride with the chitosan component and sodium tripolyphosphate with the sodium alginate component.