Chengzhi Cai

US Patent:

7637960, Dec 29, 2009

Filed:

Nov 15, 2006

Appl. No.:

11/599726

Inventors:

Chengzhi Cai - Houston TX, US
Chi-Ming Yam - Stafford TX, US
Guoting Qin - Houston TX, US
Steven Pei - Houston TX, US
Qingkai Yu - Houston TX, US

Assignee:

University of Houston - Houston TX

International Classification:

G12B 21/08

US Classification:

850 40, 73105, 850 59, 977863, 977879

Abstract:

Thin and short cantilevers possess both a low force constant and a high resonance frequency, thus are highly desirable for atomic force microscope (AFM) imaging and force measurement. According to some embodiments, the invention provides small silicon (Si) cantilevers integrated with a Si tip, for example fabricated from SOI wafers that are used for reducing the variation of thickness of the cantilevers. In one example, the fabrication process provided SOI chips containing 40 silicon cantilevers integrating with an ultra-sharp Si tip. The resolution of images obtained with these tips was much higher than those obtained with the commercial tips, while the force constants were much less, that is, more suitable for imaging soft samples. The availability of such SOI chips greatly facilitates large scale modification of the surfaces of the silicon cantilever tips with a monolayer of oligo(ethylene glycol) derivatives that resist the non-specific interactions with proteins, rendering them most suitable for imaging and measurement of biological samples.

US Patent:

8426028, Apr 23, 2013

Filed:

Apr 23, 2008

Appl. No.:

12/108217

Inventors:

Chengzhi Cai - Houston TX, US
Chin Ming Yam - Stafford TX, US
Jianhua Gu - Houston TX, US

Assignee:

University of Houston - Houston TX

International Classification:

B32B 27/32
B32B 9/04
B32B 13/04
C07H 19/00
C07H 21/00
C07H 21/02
A61K 48/00

US Classification:

428446, 428220, 428448, 502158, 514 44 R, 536 221, 536 231

Abstract:

A sensor that includes a) a silicon (Si) substrate having a surface; and b) a monolayer of oligoethylene glycol (OEG) bonded to the surface via silicon-carbon bonds. Regions of the OEG monolayer distal to the surface are functionalized with a ligand serving as a recognition element for a bioanalyte. The ligand is covalently bonded in these regions as a cycloadduct of a 1,3-dipolar cycloaddition reaction. A method of making a silicon surface that recognizes a biological specimen includes 1) hydrosilylating with a mixture that includes an oligoethylene glycol (OEG) substituted with an alkene at one end of the OEG and capped at the opposing end of the OEG and an oligoethylene glycol (OEG) substituted with an alkene at one end of the OEG and an alkyne having a protecting group at the opposing end of the OEG and 2) removing the protecting group from the alkyne; and 3) reacting the alkyne with a reagent in a 1,3-dipolar cycloaddition. The reagent in the 1,3-dipolar cycloaddition includes a portion capable of being recognized by a biological specimen.

US Patent:

8506993, Aug 13, 2013

Filed:

Aug 14, 2008

Appl. No.:

12/191946

Inventors:

Chengzhi Cai - Houston TX, US
Guoting Qin - Houston TX, US
Amit Kumar - Houston TX, US

Assignee:

University of Houston - Houston TX

International Classification:

A61K 9/14
A61K 9/127
C07D 249/04

US Classification:

424450, 514 1, 514183, 514359, 977902, 977904, 977907

Abstract:

According to some embodiments, the present invention provides compositions and methods for making and using multifunctional polymerized liposomes finding relevant application in medical sciences, particularly in bioimaging, diagnostics, drug delivery, and drug formulation. The compositions and methods involve lipids that are both polymerizable and have a “clickable” group that provides the ability to functionalize via a click reaction with various functional moieties useful for the above-listed applications.

US Patent:

20040213910, Oct 28, 2004

Filed:

Dec 19, 2003

Appl. No.:

10/742047

Inventors:

Chengzhi Cai - Houston TX, US
Chi Yam - Stafford TX, US
Zhongdang Xiao - Nanjing, CN
Jianhua Gu - Houston TX, US

Assignee:

University of Houston - Houston TX

International Classification:

B32B009/00

US Classification:

427/299000, 428/446000

Abstract:

The present invention provides for a practical method of grafting oligo- and/or poly(ethyleneglycol) (OEG and/or PEG) derivatives onto hydrogen-terminated silicon surfaces, including the surfaces of silicon scanning probe microscopy (SPM) tips, by hydrosilylation of OEG and/or PEG-terminated alkenes. This invention is related to the development of silicon-based bio-devices, including biochips, biosensors such as SPM probes, microarrays, micro-fluidic systems, and implantable microdevices. This invention is also a practical method to modify (many) SPM probe tips with OEG/PEG derivatives and to subsequently modify the tip apex with functional single molecules to improve the specificity and resolution of AFM imaging and measurements. The functional molecules include the dendritic adsorbates with a functional group at their focal point and with or without a tripod-shaped framework.

US Patent:

20070212555, Sep 13, 2007

Filed:

Apr 27, 2005

Appl. No.:

11/587232

Inventors:

Chengzhi Cai - Houston TX, US
Chin Yam - Stafford TX, US
Jianhua Gu - Houston TX, US

Assignee:

University of Houston - Houston TX

International Classification:

C12M 1/34
C12M 3/00
C12Q 1/68
G01N 21/00
G01N 31/22
G01N 33/53
G01N 33/551

US Classification:

428446000, 427255600

Abstract:

The present invention is generally directed to nanometric biomolecular arrays and to a novel approaches for the preparation of such nanoarrays, based on binding of biomolecules, such as avidin, to templates generated by lithographically-an-odizing biocompatible ultrathin films on silicon substrates using AFM anodization lithography. The present invention is also directed to methods of using such arrays.

US Patent:

20120231518, Sep 13, 2012

Filed:

Mar 12, 2012

Appl. No.:

13/418131

Inventors:

Chengzhi Cai - Houston TX, US

Assignee:

University of Houston - Houston TX

International Classification:

C12N 11/08

US Classification:

435180

Abstract:

According to some embodiments, the present invention provides a modified silicone surface for interference to pathogen colonization comprising: an activated silicone layer; a plurality of cross-linking dendrimers adsorbed onto to the activated silicone layer; a plurality of ligand derivatives, each bound to at least one of the plurality of cross-linking dendrimers; and a benign biofilm adhered to the plurality of ligand derivatives. According to some embodiments, the present invention provides a method for making a modified silicone surface for interference to pathogen colonization comprising activating a silicone surface; adsorbing a plurality of cross-linking dendrimers to the silicone surface; binding a plurality of ligand derivatives to the plurality of cross-linking dendrimers; and adhering a benign biofilm to the plurality of ligand derivatives.

US Patent:

20130296574, Nov 7, 2013

Filed:

Mar 25, 2013

Appl. No.:

13/850210

Inventors:

Chengzhi Cai - Houston TX, US
Chin Ming Yam - Stafford TX, US
Jianhua Gu - Houston TX, US

International Classification:

B01J 31/22
G01N 33/50

US Classification:

548109

Abstract:

A sensor that includes a) a silicon (Si) substrate having a surface; and b) a monolayer of oligoethylene glycol (OEG) bonded to the surface via silicon-carbon bonds. Regions of the OEG monolayer distal to the surface are functionalized with a molecular probe serving as a recognition element for a bioanalyte. The molecular probe is covalently bonded in these regions as a cycloadduct of a 1,3-dipolar cycloaddition reaction. A composition having use as a catalyst for a 1,3-dipolar cycloaddition reaction includes Cu(I) and a triazole ligand having an oligoethylene glycol substituent. A method of making a silicon surface that recognizes a biological specimen includes 1) hydrosilylating with a mixture that includes an oligoethylene glycol (OEG) substituted with an alkene at one end of the OEG and capped at the opposing end of the OEG and an oligoethylene glycol (OEG) substituted with an alkene at one end of the OEG and an alkyne having a protecting group at the opposing end of the OEG and 2) removing the protecting group from the alkyne; and 3) reacting the alkyne with a reagent in a 1,3-dipolar cycloaddition. The reagent in the 1,3-dipolar cycloaddition includes a portion capable of being recognized by a biological specimen.

US Patent:

20130324738, Dec 5, 2013

Filed:

May 14, 2013

Appl. No.:

13/894101

Inventors:

Chengzhi Cai - Houston TX, US
Guoting Qin - Houston TX, US
Amit Kumar - Houston TX, US

Assignee:

University of Houston - Houston TX

International Classification:

C08F 4/04

US Classification:

548101

Abstract:

According to some embodiments, the present invention provides compositions and methods for making and using multifunctional polymerized liposomes finding relevant application in medical sciences, particularly in bioimaging, diagnostics, drug delivery, and drug formulation. The compositions and methods involve lipids that are both polymerizable and have a “clickable” group that provides the ability to functionalize via a click reaction with various functional moieties useful for the above-listed applications.