A polymer comprising recurring units represented by formula (I): 1 wherein X is selected from the group consisting of C(O)OR1, C(O)SR1, C(O)NR1R2, and VZ, where R1 and R2 are each individually selected from the group consisting of hydrogen, C1 to C10 alkyl, and C6 to C10 aryl, where V is a labile linker group, and where Z is selected from the group consisting of poly(ethyleneimine), poly(propyleneimine), poly(lysine), PAMAM dendrimer, octaamine dendrimer, and hexadecaamine dendrimer; and wherein Y is selected from the group consisting of null(CH2)2null, null(CH2)2nullOnull(CH2)2null, null(CH2)2nullOnull(CH2)2nullOnull(CH2)2null, and null(CH2)3nullNHC(O)null(CH2)6nullC(O)NHnull(CH2)3null is useful in nucleic acid delivery applications. Polyacetals of the formula (I) are preferably made by reacting appropriate diols and divinyl ethers. In preferred embodiments, complexes formed between polyacetals of the formula (I) and polynucleotides are useful as transfection reagents.