Abstract: Intact, bacterially-derived minicells can safely introduce therapeutically effective amounts of plasmid-free functional nucleic acid to target mammalian cells. To this end, functional nucleic acid can be packaged into intact minicells directly, without resort to expression constructs, the expression machinery of the host cell, harsh chemicals or electroporation.
Type:
Grant
Filed:
December 29, 2010
Date of Patent:
March 11, 2014
Assignee:
Engeneic Molecular Delivery Pty. Ltd.
Inventors:
Himanshu Brahmbhatt, Jennifer MacDiarmid, Toby Hulf
Abstract: A composition comprising intact killed bacterial cells that contain a therapeutic nucleic acid, a drug or a functional nucleic acid is useful for targeted delivery to mammalian cells. The targeted delivery optionally employs bispecific ligands, comprising a first arm that carries specificity for a killed bacterial cell surface structure and a second arm that carries specificity for a mammalian cell surface receptor, to target killed bacterial cells to specific mammalian cells and to cause endocytosis of the killed bacterial cells by the mammalian cells. Alternatively, the delivery method exploits the natural ability of phagocytic mammalian cells to engulf killed bacterial cells without the use of bispecific ligands.
Type:
Grant
Filed:
July 15, 2011
Date of Patent:
November 26, 2013
Assignee:
Engeneic Molecular Delivery Pty Ltd
Inventors:
Himanshu Brahmbhatt, Jennifer Macdiarmid
Abstract: The present invention provides a method for purifying bacterial minicells that involves subjecting a sample containing minicells to density gradient centrifugation in a biologically compatible medium. The method optionally includes a preliminary differential centrifugation step and one or more filtration steps. The invention also provides a method for purifying bacterial minicells in which a sample containing minicells is subjected to a condition that induces parent bacterial cells to adopt a filamentous form, followed by filtration of the sample to separate minicells from parent bacterial cells. The inventive methods optionally include one or more steps to remove endotoxin from purified minicell preparations, and/or treatment of purified minicell preparations with an antibiotic. Additionally, the invention provides purified minicell preparations, prepared according to the foregoing methods, and containing fewer than about 1 contaminating parent bacterial cell per 107, 108, 109, 1010, or 1011 minicells.
Type:
Application
Filed:
April 17, 2013
Publication date:
September 12, 2013
Applicant:
EnGeneIC Molecular Delivery Pty. Ltd.
Inventors:
Himanshu Brahmbhatt, Jennifer MacDiarmid
Abstract: The present invention provides a method for purifying bacterial minicells that involves subjecting a sample containing minicells to density gradient centrifugation in a biologically compatible medium. The method optionally includes a preliminary differential centrifugation step and one or more filtration steps. The invention also provides a method for purifying bacterial minicells in which a sample containing minicells is subjected to a condition that induces parent bacterial cells to adopt a filamentous form, followed by filtration of the sample to separate minicells from parent bacterial cells. The inventive methods optionally include one or more steps to remove endotoxin from purified minicell preparations, and/or treatment of purified minicell preparations with an antibiotic. Additionally, the invention provides purified minicell preparations, prepared according to the foregoing methods, and containing fewer than about 1 contaminating parent bacterial cell per 107, 108, 109, 1010, or 1011 minicells.
Type:
Grant
Filed:
April 4, 2011
Date of Patent:
May 28, 2013
Assignee:
Engeneic Molecular Delivery Pty. Ltd.
Inventors:
Himanshu Brahmbhatt, Jennifer MacDiarmid
Abstract: The present invention provides a method for purifying bacterial minicells that involves subjecting a sample containing minicells to density gradient centrifugation in a biologically compatible medium. The method optionally includes a preliminary differential centrifugation step and one or more filtration steps. The invention also provides a method for purifying bacterial minicells in which a sample containing minicells is subjected to a condition that induces parent bacterial cells to adopt a filamentous form, followed by filtration of the sample to separate minicells from parent bacterial cells. The inventive methods optionally include one or more steps to remove endotoxin from purified minicell preparations, and/or treatment of purified minicell preparations with an antibiotic. Additionally, the invention provides purified minicell preparations, prepared according to the foregoing methods, and containing fewer than about 1 contaminating parent bacterial cell per 107, 108, 109, 1010, or 1011 minicells.
Type:
Grant
Filed:
March 27, 2007
Date of Patent:
August 23, 2011
Assignee:
Engeneic Molecular Delivery Pty. Ltd.
Inventors:
Himanshu Brahmbhatt, Jennifer MacDiarmid
Abstract: The present invention provides a method for purifying bacterial minicells that involves subjecting a sample containing minicells to density gradient centrifugation in a biologically compatible medium. The method optionally includes a preliminary differential centrifugation step and one or more filtration steps. The invention also provides a method for purifying bacterial minicells in which a sample containing minicells is subjected to a condition that induces parent bacterial cells to adopt a filamentous form, followed by filtration of the sample to separate minicells from parent bacterial cells. The inventive methods optionally include one or more steps to remove endotoxin from purified minicell preparations, and/or treatment of purified minicell preparations with an antibiotic. Additionally, the invention provides purified minicell preparations, prepared according to the foregoing methods, and containing fewer than about 1 contaminating parent bacterial cell per 107, 108, 109, 1010, or 1011 minicells.
Type:
Grant
Filed:
June 24, 2003
Date of Patent:
November 3, 2009
Assignee:
Engeneic Molecular Delivery Pty, Ltd.
Inventors:
Himanshu Brahmbhatt, Jennifer MacDiarmid
Abstract: A composition comprising recombinant, intact minicells that contain a therapeutic nucleic acid molecule is disclosed. Methods for purifying a preparation of such minicells also are disclosed. Additionally, a genetic transformation method is disclosed, which comprises (i) making recombinant, intact minicells available that contain a plasmid comprised of a first nucleic acid segment, and (ii) bringing the minicells into contact with mammalian cells that are engulfing-competent, such that the minicells are engulfed by the mammalian cells, which thereafter produce an expression product of the first nucleic acid segment.
Type:
Application
Filed:
January 24, 2008
Publication date:
August 7, 2008
Applicant:
EnGeneIC Molecular Delivery Pty. Ltd.
Inventors:
Himanshu BRAHMBHATT, Jennifer Macdiarmid