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Suspensive condition in contracts is the one that takes effect from occurrence of another event based on the contents of the contract and resolutive condition is an arrangement between the parties that an agreement will end in the event of certain circumstances. Despite the conditional unity of nature of the two institutions, the distinction in the subject of their conditionality has created different rulings and effects. This paper, reviews the difference between the two institutions in terms of rulings and effects, with focus on Imam Khomeini’s views, while offering a thorough definition of the two and the general rules on suspensive condition in contracts and its cancellation. This study will show that in view of Imam Khomeini, whereas suspensive contract occurs in its composition, until before realization of the condition, no contract shall be considered effective, hence no obligation will be created and no conveyance shall be made either. However, under resolutive condition, a full contract is made first but with the occurrence of the condition, the considerations will be withdrawn by either owner or party. Therefore, in suspensive contract, the owners will be entitled to possess their property by all means and ways, but in conditional agreement, the conveyee is obliged to preserve the objection of conveyance, although violation of this imperative rule does not have any dispositive effect.

Adeno-associated viruses (AAVs) have been well characterized and used to deliver therapeutic genes for diseases treatment in clinics and basic research. This study used the triple transient transfection of AAV-DJ/8 as a model expression system to develop and optimize the laboratory production of AAV for research and pre-clinical applications. Specifically, various production parameters, including host cell, transfection reagent, cell density, ratio of plasmid DNA and cells, gene size, and production mode, were tested to determine the optimal process. Our results showed that the adherent production using HEK 293AAV with calcium transfection generated the highest volumetric productivity of 7.86 × 109 gc/ml. The optimal suspensive production using HEK 293F had best AAV productivity of 5.78 × 109 gc/ml in serum-free medium under transfection conditions of transfection density of 0.4 × 106 cells/ml, plasmid DNA:cells ratio of 1.6 µg:106 cells and synthesized cationic liposomes as transfection reagent. The similar AAV productivity was confirmed at scales of 30–450 ml in shaker and/or spinner flasks. The in vitro transfection and in vivo infection efficiency of the harvested AAV-DJ/8 carrying luciferase reporter gene was confirmed using cell line and xenograft mouse model, respectively. The minimal or low purification recovery rate of AAV-DJ/8 in ion-exchange chromatography column and affinity column was observed in this study. In summary, we developed and optimized a scalable suspensive production of AAV to support the large-scale preclinical animal studies in research laboratories.

Adeno-associated viruses (AAVs) have been well characterized and used to deliver therapeutic genes for diseases treatment in clinics and basic research. This study used the triple transient transfection of AAV-DJ/8 as a model expression system to develop and optimize the laboratory production of AAV for research and pre-clinical applications. Specifically, various production parameters, including host cell, transfection reagent, cell density, ratio of plasmid DNA and cells, gene size, and production mode, were tested to determine the optimal process. Our results showed that the adherent production using HEK 293AAV with calcium transfection generated the highest volumetric productivity of 7.86x10 9 gc/mL. The optimal suspensive production using HEK 293F had best AAV productivity of 5.78x10 9 gc/mL in serum-free medium under transfection conditions of transfection density of 0.4x10 6 cells/mL, plasmid DNA:cells ratio of 1.6 μg:10 6 cells and synthesized cationic liposomes as transfection reagent. The similar AAV productivity was confirmed at scales of 30 mL - 450 mL in shaker and/or spinner flasks. The in vitro transfection and in vivo infection efficiency of the harvested AAV-DJ/8 carrying luciferase reporter gene was confirmed using cell line and xenograft mouse model, respectively. The minimal or low purification recovery rate of AAV-DJ/8 in ion-exchange chromatography column and affinity column was observed in this study. In summary, we developed and optimized a scalable suspensive production of AAV to support the large-scale preclinical animal studies in research laboratories., Competing Interests: Conflicts of Interest The authors declare no conflict of interest.