the novel administration and treatment means of the invention results from knowledge of a parasitic nematode , the ascaris roundworm life cycle in human beings , as detailed below . ascaris lumbricoides is one of the largest and most common parasites found in humans . the adult females of this species can measure up to 18 inches long ( males are generally shorter ), and it is estimated that 25 % of the world &# 39 ; s population is infected with this nematode . the adult worms live in the small intestine and eggs are passed in the faeces . a single female can produce up to 200 , 000 eggs each day . about two weeks after passage in the faeces the eggs contain an infective larval or juvenile stage , and humans are infected when they ingest such infective eggs . the eggs hatch in the small intestine , the juvenile penetrates the small intestine and enters the circulatory system , and quickly the juvenile worm makes its way to the capillaries of the lungs . in the lung capillaries the juvenile worm secrets proteolytic enzymes from its mouth . these enzymes act upon the cells of the capillary wall . the wall ultimately breaks down and the worm is able to move across the blood - air barrier into the lung . the juvenile worm then migrates up the air passages into the pharynx where it is swallowed , and once in the small intestine the juvenile grows into an adult worm . examples of specific worm proteases include the strongyloides stercoralis — the larvae of this nematode parasite can move through tissue at speeds of up to 10 cm per hour . this nematode larvae secrete a potent histolytic metalloprotease to facilitate the rapid migration . this protease has elastase activity and catalyses the degradation of a model of dermal extracellular matrix . ascaris suum , in the tissue - invasive infective and lung stage larvae release proteinases . specifically , this activity contained multiple proteolytic enzyme activities , particularly chymotryptic , tryptic collagenolylic and elastolytic activities . the novel administration means of the invention employs the method of blood - air barrier movement exhibited by the worm . the active agent , which in the examples considered here , is useful in treatment of cystic fibrosis , is brought into the vicinity of the lung capillary and , with the excretion or otherwise application of proteases , is able to cross the boundary into the lung . it will be appreciated by one skilled in the art that although this discussion is primarily concerned with cystic fibrosis the novel administration method of the invention may well be used to treat other lung conditions as it allows a cell or a treatment species access to the lung . in the case of cystic fibrosis the “ treatment species ” is one or more cells having normal cftr production . in other applications the treatment species may be other drugs ( anticancer , asthma drugs etc ) or other chemical or biological bio - actives for which will have some effect in the lung . an essential process in the invention is access of the treatment species into the lung via access to the lung epithelia . the result could be incorporation of the treatment species ( or a derivative ) into the epithelial layer as is the case with cftr functioning cells . alternatively access to the lung epithelia of the treatment species could result in access through the epithelia by disruption or otherwise , of the treatment species into the lung itself . the “ active agent ” contemplated here is cellular material from a suitable mammal donor . more specifically it may take one of ( but is not restricted to ) three forms : i ) human cells in which the cftr protein is present ( in other words , the chloride pump is functioning ); ii ) porcine cells in which the cftr protein is present ; iii ) human stem cells . the cells are administered in the form of a biological delivery device . this is more specifically encapsulated cells , or encapsulated cell clusters . the following outlines our preferred methodology for creation of the device but it will be appreciated other known variations or alternatives for this methodology may also be included without departing from the scope of the invention . cells taken from healthy humans ( not having cystic fibrosis ) cells taken from other suitable mammalian species ( such as pigs ) cells taken from transgenic species not having the defective gene . human stem cells . in our preferred method we prepare clusters of cells which will then be encapsulated . as the size of the overall device is crucial in the method of the invention ( ultimately a device in range 20 - 80 micrometers is desired ) then a cluster of & lt ; 70 micrometers is ( pre - encapsulation ) required to provide this size . we have prepared micro clusters of porcine lung epithelia according to the following method . i . dissection of parenchyma from large vessels and airways of the donor species ii . removal of red blood cells iii . digestion with liberase or similar iv . addition of nutrient media ( including rpmi , nicotinamide , human serum albumin , pig serum , aproxin ) v . removal of gross clumps by filtration vi . segmentation and resuspension in the nutrient medium vii . culture in non - adherent culture dishes ( up to one month ) an example lung cluster prepared by such a method is shown in fig1 . the image is a uv / phase contrast the spheroid being some 60 micrometers in diameter . fig2 illustrates a number of such clusters . our cell transplant work has shown that transplanted cells even from foreign species can be protected from rejection after transplantation without the need to use severe immune suppressing drugs . this is done by coating the cells or clusters of such cells with ‘ micro - capsules ’, which allow the required cell secretion out , and nutrients in but excludes the larger components of the immune system . smaller components can be neutralised by use of nicotinamide - a harmless vitamin derivative . one particular encapsulation process ( as an example ) follows . it employs alginate as an encapsulation material but equally other in vivo similarly behaving materials may be employed . take a population of cells ( or cell clusters ) to be transplanted encapsulate or encase in an alginate coating apply polyornithine coat once more in alginate the proteolytic enzyme may be inserted on top of the polyornithine before application of the second coating of alginate . alternatively it may be mixed with the final alginate coating in the form , for example as gelatin ( or other suitable ) microcapsules . the outermost alginate coating will dissolve relatively quickly in blood of the patient ( for example within 2 days ) to expose the proteolytic enzyme . with particular reference to fig3 , a form of preferred device of the invention is illustrated . in particular we have shown preparation of triple - layered encapsulation lung epithelial structures , as organotypic structures with beaded protease clusters . ( a ) porcine lung epithelia are prepared in modified cell culture media as spheroidal organotypic structures , the spheroid having an outer layer of epithelial cells a lumen filled with liquid . ( b ) a first layer of alginate outside the cells is deposited by calcium gelation . ( c ) the outer surface of the alginate is stabilised with a layer of poly - l - ornithine . preferably the beaded clusters of proteases are deposited with the poly - l - ornithine layer . ( d ) there is an option for a third layer of alginate to cover the protease beads in order to conserve their activity . the delivery mode takes advantage of the circulation system , in particular the venous system . the delivery device is injected into a vein and then moves through the system until it reaches the smaller diameter capillaries of the lungs . as a result of the decreasing capillary size the device will eventually get “ jammed ” or impact in the vessel in the lung . the impaction may also cause compaction of the device . the size of the device is crucial to the working of the invention . it must be large enough to impact in the capillary system within the lung but small enough not to lodge earlier in the venous system . lung capillaries are approximately 7 - 13μ diameter . this lung microvasulative has a diameter less than 100μ . once the device is impacted , via the structure of the outer wall of the device is destabilised and the proteases released such that they come into contact with the capillary wall . the capillary wall will then breakdown admitting the ( residue of ) the device , and specifically the treatment cells . the treatment cells then , come into contact with the epithelial cells inside the lung surface . as has been known in the prior art the similar properties of the treatment cells allow merging of the treatment cells with the epithelial cells to form micro chimaeric clusters within the lung ( a mixture of the two cells types ). ultimately , the human capillary wall reorganises itself whilst the epithelial cells now include treatment cells with a healthy chloride pump activity on the lung wall . with particular reference to fig4 we have illustrated an example of impaction of encapsulated lung structures through blood - air barrier and integration into the patient &# 39 ; s airway structure . in stage one the capsules are injected into a suitable vein , travel in the venous blood to the lung where the narrow capillaries prevent onward movement and the structure is impacted and compressed and the capsule structure compromised . in stage two the outer surface of the capsule structure is sufficiently compromised to release the protease beads that degrade the capillary wall and the basal layer of the airway epithelium , releasing epithelial cells in a focal area in stage three the encapsulated cells are released from the capillary into the epithelial layer where they integrate as a micro - chimaeric group of cells capable of expressing cftr and promoting chloride transport and water secretion . the assimilated cells should start to cause water transport into the lung linings via the chloride pumping system . cystic fibrosis studies have shown you only need & lt ; 1 % of total chloride pumping ability to significantly decrease cystic fibrosis symptoms . administration is via the venous system thus the administered devices may proceed via the capillary system to all areas of the lung . this is an advantage over prior art treatment methods which generally only allow treatment in one specific area . where in the foregoing description reference has been made to elements or integers having known equivalents , then such equivalents are included as if they were individually set forth . although the invention has been described by way of example and with reference to particular embodiments , it is to be understood that modifications and / or improvements may be made without departing from the scope or spirit of the invention .
the invention relates to a novel method of administration , and device employed in the method , for administering a treatment species to the lungs of a recipient patient . the method involves introducing the device of the invention to the venous system of the patient , the size of the treatment species being such that , upon introduction to the venous system of the patient , the device will impact in a region of a lung capillary of the patient . the treatment species gains access to the lung and / or lung epithelia due to proteases associated with the treatments species . the application of the method to the treatment of cystic fibrosis is also claimed .