The lesson here is probably above all a cautionary tale about loose language. In its full context, it appears that the patentee was merely providing examples of conventional methods used for two-dimensional culturing and not intending to disclaim any particular method should it be somehow applied to three-dimensional culturing. Nevertheless, the court applied the standard tenet of claim construction that disclaiming the ordinary meaning of a claim term – and thus, in effect, redefining it – can be effected through “repeated and definitive remarks in the written description.” One should therefore take care to contrast apples with apples, distinguishing here between cells grown in (a) three-dimensions from cells grown in (b) two-dimensions (“such as” those conventionally grown on beads) rather than distinguishing over individual techniques directly.
Background / Facts: The patents being asserted here are directed to producing pharmaceutical compositions containing “novel conditioned cell culture medium compositions,” which provide in vitro environments for harvesting “a variety of cellular metabolites and secreted proteins” produced by cells in the culture, including “biologically active growth factors, inflammatory mediators and other extracellular proteins.” According to the patentees, a novel and important aspect of their invention is the difference between the conditioned medium produced by cells cultured in two-dimensions and in three-dimensions. “While growth of cells in two dimensions is a convenient method for preparing, observing and studying cells in culture,” two-dimensional cultures lack “characteristic[s] of whole tissue in vivo.” In this regard, the claims include the limitation that the cell culture medium used in the inventions must be conditioned by “culturing … cells in three-dimensions.” The specification distinguishes between “[c]ell lines grown as a monolayer or on beads, as opposed to cells grown in three-dimensions.” The accused culturing method in fact begins as “one- or two-dimensional growth” on beads, but then “evolves into a three-dimensional growth phase in which the cells crawl off the beads.”
Issue(s): Whether the claimed “culturing … cells in three-dimensions” covers the three-dimensional culturing involving growth on beads as in the accused culturing method.
Holding(s): No. The court freely acknowledged that “[i]n this case, the ordinary meaning of ‘culturing … cells in three-dimensions’ would reach the use of beads,” but found that “[t]he specification clearly proves that the patentees defined the three-dimensional culturing required by the claims to exclude culturing with beads, because the patent expressly confines culturing with beads to two-dimensional culturing.” In particular, the court noted that “[t]he patentees refer to ‘beads five times in the intrinsic record” and “[i]n each and every one of those … references, the patentees clearly distinguish culturing with beads from culturing in three-dimensions.” When the specification distinguishes, for example, between “[c]ell lines grown as a monolayer or on beads, as opposed to cells grown in three-dimensions,” “[i]t is quite apparent from the use of the disjunctive phrase ‘as opposed to’ that the patentees considered cells grown on beads to be different and distinct from cells grown in what they considered to be three-dimensions.”