6 research outputs found
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Enforcing Disclosure Compliance in Mergers and Acquisitions: Evidence from China
This study examines how enforcement of acquisition disclosure regulation affects investors’ assessment of the transactions’ quality at merger and acquisition (M&A) announcements. Using a novel sample of comment letters on acquisition filings by public companies in China, we document that regulatory requests for disclosure enhancement and clarifications are more common on lower quality transactions obfuscated by weaker disclosure as evidenced by (i) a lower likelihood of the deal closing, and if the deal does close, lower post-deal firm profitability; and, (ii) a greater likelihood of subsequent goodwill impairment. Using entropy balancing matching, we document that transactions that receive comment letters associate with significant negative bidder announcement returns suggesting that regulatory actions reveal new information that aids investors to identify lower quality deals. The negative price effect is greater when comment letters have more acquisition-specific comments, compared to letters with more comments on general accounting and governance issues. Our results showcase that enforcing disclosure compliance in M&A filings aids investors in assessing the quality of M&A transactions at the time when the filings are made public
A novel chitosan-based nanomedicine for multi-drug resistant breast cancer therapy
In this study, a novel chitosan-based (CS) nanocarrier was developed for doxorubicin (DOX) and oleanolic acid (OA) co-delivery. CS was first functionalized with folic acid to allow selective uptake by cancer cells, and then subsequently with OA. The resultant copolymer self-assembled into nanoparticles (NPs) upon addition to water. These FA-CS-g-OA@DOX nanoparticles (NPs) had appropriate size (180 nm) and size distribution (PDI < 0.45) for tumor therapy, as well as a high drug-loading efficiency (15.6 % w/w DOX; 5.1% w/w OA) and pH-responsive release properties. In breast cancer MDA-MB-231 cells, more efficient uptake of FA-CS-g-OA@DOX NPs than of free DOX was observed by confocal laser scanning microscopy and flow cytometry. The in vitro cytotoxicity of FA-CS-g-OA@DOX NPs against MDA-MB-231 cells was higher than with free DOX and free OA, while the NPs were less harmful to healthy HUVEC cells. In vivo pharmacokinetic studies showed that FA-CS-g-OA@DOX NPs had a much longer circulation time than free DOX, while biodistribution results revealed that FA-CS-g-OA@DOX could actively target a MDA-MB-231 xenograft tumor in mice. The NPs are found to have apoptosis-enhancing and anti-proliferative capacities in vivo. The presence of OA in the formulation both sensitizes cancer cells to DOX and mitigates DOX-induced damage to healthy tissues. The FA-CS-g-OA@DOX NPs generated in this work hence have great potential for the treatment of multi-drug resistant breast cancers, and further offer a platform to target other cancers