To determine the most efficient in vivo delivery method of at 7 days after transfection. We then introduced antisense oligonucleotides for antisense therapy in ligament healing, ODN for the rabbit proteoglycan, decorin, into ligament fluorescence-labelled phosphorothioate oligodeoxynuleoscars with this delivery method and confirmed a significant tides (ODN) were introduced into 12 rabbit ligament scars inhibition of decorin mRNA expression in antisense-treated 2 weeks after injury using haemagglutinating virus of Japan scar tissues in vivo both at 2 days (42.3 ± 14.7% of sense (Sendai virus; HVJ)-conjugated liposomes. We compared control ± s.d.; P Ͻ 0.0025) and 3 weeks (60.5 ± 28.2% of the efficiency of cellular uptake of fluorescence as a persense control ± s.d.; P Ͻ 0.024) after treatment, compared centage of all cells in each scar using three delivery prowith sense ODN-treated scars. Decorin was significantly cedures: (1) direct free-hand injection into the ligament suppressed also at protein level in antisense-treated scars scar using a conventional syringe; (2) systematic direct at 4 weeks (66.6 ± 35.7% of sense control ± s.d.; scar injection using a repeating 10 l dispenser and a P Ͻ 0.045) after treatment. These results demonstrate that square mesh grid system; and (3) injection into the feeding in vivo transfection efficiency in ligament scars is 'delivery (femoral) artery. Results showed that there was a signifisystem dependent' and that introduction of antisense ODN cant difference in fluorescence uptake by scar cells on day for the small proteoglycan, decorin, with this delivery 1 after injection between the three delivery methods: (1) method can lead to significant suppression of its direct free-hand, 9.7 ± 7.6% (average ± s.d.); (2) systemexpression over 3 weeks both at mRNA and protein levels. atic direct, 58.4 ± 15.9%; and (3) intra-arterial, 0.2 ± 0.1%.Thus, an effective model for the potential manipulation of Systematic direct injection was most efficient and it scar composition and quality in ligament healing has resulted in 25.9 ± 13.0% of scar cells being labeled been established.