Severity: Warning
Message: fopen(/var/lib/php/sessions/ci_sessionpacr2s48j98nbvuoolkp660ds0f8g87i): Failed to open stream: No space left on device
Filename: drivers/Session_files_driver.php
Line Number: 177
Backtrace:
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)
Filename: Session/Session.php
Line Number: 137
Backtrace:
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "choices"
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 249
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: 8192
Message: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated
Filename: models/Detail_model.php
Line Number: 71
Backtrace:
File: /var/www/html/application/models/Detail_model.php
Line: 71
Function: strpos
File: /var/www/html/application/controllers/Detail.php
Line: 252
Function: insertAPISummary
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: 8192
Message: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
Filename: helpers/my_audit_helper.php
Line Number: 8919
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 8919
Function: str_replace
File: /var/www/html/application/controllers/Detail.php
Line: 255
Function: formatAIDetailSummary
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "choices"
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 256
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 257
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 257
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 257
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 257
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 258
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 258
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 258
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 258
Function: _error_handler
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 259
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 259
Function: _error_handler
File: /var/www/html/index.php
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Function: require_once
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Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
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File: /var/www/html/application/controllers/Detail.php
Line: 259
Function: _error_handler
File: /var/www/html/index.php
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Function: require_once
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 260
Backtrace:
File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler
File: /var/www/html/index.php
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Function: require_once
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 260
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File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler
File: /var/www/html/index.php
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Function: require_once
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Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 260
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File: /var/www/html/application/controllers/Detail.php
Line: 260
Function: _error_handler
File: /var/www/html/index.php
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Function: require_once
Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 143
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 143
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
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Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
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Function: getPubMedXML
File: /var/www/html/application/helpers/my_audit_helper.php
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Function: GetPubMedArticleOutput_2016
File: /var/www/html/application/controllers/Detail.php
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Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
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Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
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Function: require_once
To serve as artificial matrices for therapeutic cell transplantation, synthetic hydrogels must incorporate mechanisms enabling localized, cell-mediated degradation that allows cell spreading and migration. Previously, we have shown that hybrid semi-interpenetrating polymer networks (semi-IPNs) composed of hydrolytically degradable poly(ethylene glycol) diacrylates (PEGdA), acrylate-PEG-GRGDS and native hyaluronic acid (HA) support increased cell spreading relative to fully synthetic networks that is dependent on cellular hyaluronidase activity. This study systematically investigated the effects of PEGdA/HA semi-IPN network composition on 3-D spreading of encapsulated fibroblasts, the underlying changes in gel structure responsible for this activity, and the ability of optimized gel formulations to support long-term cell survival and migration. Fibroblast spreading exhibited a biphasic response to HA concentration, required a minimum HA molecular weight, decreased with increasing PEGdA concentration and was independent of hydrolytic degradation at early time points. Increased gel turbidity was observed in semi-IPNs, but not in copolymerized hydrogels containing methacrylated HA, which did not support cell spreading. This suggests that there is an underlying mechanism of polymerization-induced phase separation that results in HA-enriched defects within the network structure. PEGdA/HA semi-IPNs were also able to support cell spreading at relatively high levels of mechanical properties (∼10kPa elastic modulus) compared to alternative hybrid hydrogels. In order to support long-term cellular remodeling, the degradation rate of the PEGdA component was optimized by preparing blends of three different PEGdA macromers with varying susceptibility to hydrolytic degradation. Optimized semi-IPN formulations supported long-term survival of encapsulated fibroblasts and sustained migration in a gel-within-gel encapsulation model. These results demonstrate that PEGdA/HA semi-IPNs provide dynamic microenvironments that can support 3-D cell survival, spreading and migration for a variety of cell therapy applications.
Download full-text PDF |
Source |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4313787 | PMC |
http://dx.doi.org/10.1016/j.actbio.2014.12.007 | DOI Listing |
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