Peter Ma - Academia.edu (original) (raw)

Papers by Peter Ma

Biomaterials, 2019

Nanostructures formed with bioactive peptides offer an exciting prospect in clinical oncology as ... more Nanostructures formed with bioactive peptides offer an exciting prospect in clinical oncology as a novel class of therapeutic agents for human cancers. Despite their therapeutic potential, however, peptide-based nanomedicines are often inefficacious in vivo due to low cargo-loading efficiency, poor tumor cell-targeting specificity and limited drug accumulation in tumor tissues. Here, we describe the design, via assembly of a p53-activating peptide termed PMI, functionalized PEG and fluorescent lanthanide oxyfluoride nanocrystals, of a novel nanotheranostic shaped in flexible rods. This lanthanide-peptide nanorod or LProd of bionic nature exhibited significantly enhanced tumor-targeting and-imaging properties compared to its spherical counterpart. Importantly, LProd potently inhibited tumor growth in a mouse model of human colon cancer through activating tumor suppressor protein p53 via MDM2/MDMX antagonism, while maintaining a highly favorable biosafety profile. Our data demonstrate that LProd as a multifunctional theranostic platform is ideally suited for tumor-specific peptide drug delivery with real-time disease tracking, thereby broadly impacting clinical development of antitumor peptides.

Biomacromolecules, 2018

Electrically conducting polymers such as polyaniline, polypyrrole, polythiophene and their deriva... more Electrically conducting polymers such as polyaniline, polypyrrole, polythiophene and their derivatives (mainly aniline oligomer and poly(3,4-ethylenedioxythiophene)) with good biocompatibility find wide applications in biomedical fields including bioactuators, biosensors, neural implants, drug delivery systems and tissue engineering scaffolds. This review focuses on these conductive polymers for tissue engineering application. Conductive polymers exhibited promising conductivity as bioactive scaffolds for tissue regeneration and their conductive nature allows cells or tissue cultured on them to be stimulated by electrical signals. However, their mechanical brittleness and poor processability restrict their application. Therefore, conductive polymeric composites based on conductive polymers and biocompatible biodegradable polymers (natural or synthetic) were developed. The major objective of this review is to summarize the conductive biomaterials used in tissue engineering including conductive composite films, conductive nanofibers, conductive hydrogels, and conductive composite scaffolds fabricated by various methods such as electrospinning, coating or deposition by in situ polymerization. Furthermore, recent progress in tissue engineering applications by using these conductive biomaterials including bone tissue engineering, muscle tissue engineering, nerve tissue engineering, cardiac tissue engineering, and wound healing application are discussed in detail.

Journal of Materials Chemistry B, 2016

Injectable supramolecular and covalent bonds crosslinked hydrogels with rapid self-healing and re... more Injectable supramolecular and covalent bonds crosslinked hydrogels with rapid self-healing and recovery properties were prepared via a facile approach under metal-free conditions.

Biomaterials, 2020

Lower back pain is mainly caused by intervertebral disc degeneration, in which calcification is f... more Lower back pain is mainly caused by intervertebral disc degeneration, in which calcification is frequently involved. Here novel nanofibrous spongy microspheres (NF-SMS) are used to carry rabbit bone marrow mesenchymal stromal cells (MSCs) to regenerate nucleus pulposus tissues. NF-SMS are shown to significantly enhance the MSC seeding, proliferation and differentiation over control microcarriers. Furthermore, a hyperbranched polymer (HP) with negligible cytotoxicity and high microRNA (miRNAs) binding affinity is synthesized. The HP can complex with anti-miR-199a and self-assemble into "double shell" polyplexes which are able to achieve high transfection efficiency into MSCs. A double-emulsion technique is used to encapsulate these polyplexes in biodegradable nanospheres (NS) to enable sustained anti-miR-199 delivery. Our results demonstrate that MSC/HP-anti-miR-199a/NS/NF-SMS constructs can promote the nucleus pulposus (NP) phenotype and resist calcification in vitro and in a subcutaneous environment.

Annals of Biomedical Engineering, 2000

Journal of Controlled Release, 2020

Please cite this article as: W.B. Swanson, T. Gong, Z. Zhang, et al., Controlled release of odont... more Please cite this article as: W.B. Swanson, T. Gong, Z. Zhang, et al., Controlled release of odontogenic exosomes from a biodegradable vehicle mediates dentinogenesis as a novel biomimetic pulp capping therapy,

Advanced Biosystems, 2017

especially miRNA transfection and delivery need to be improved. The transfection or delivery of m... more especially miRNA transfection and delivery need to be improved. The transfection or delivery of miRNA to target cells could efficiently treat various human diseases such as cancers and cardiovascular diseases, but has been limited by the low membrane permeability and poor serum stability of miRNAs. [4-6] Although cationic polymers and liposomes are widely investigated as nonviral vectors to overcome the intrinsic weaknesses of nucleotides, their miRNAs delivery was always unsatisfactory due to their cytotoxicity and uncontrollability. [7-9] To overcome these limitations, it is very necessary to develop next generation nonviral vectors with high miRNA delivery efficiency, minimal cytotoxicity, and smart responsive release. [10] Theta defensin (θ-defensin), a family of arginine-rich humanized antimicrobial cyclopeptides with large β-sheet structures stabilized by disulfide linkages and connected by turns, is well known for its antivirus and antibacterial activity via destabilizing the microprotein by the high positive charge density of defensin. [11-13] Previous studies have shown that θ-defensin is nontoxic and nonimmunogenic in vitro and in vivo, suggesting its great biocompatibility. [14-16] θ-defensin can also suppress the production of proinflammatory cytokines and modulate the immune response, indicating its potential in disease therapy. [17-19] Additionally, the Arg-Gly-X (RGX) sequence-contained structure Synthetic cationic vectors have shown great promise for nonviral gene delivery. However, their cytotoxicity and low efficiency impose great restrictions on clinic applications. To push through this limitation, humanized peptides or proteins with cationic biocompatibility as well as biodegradation would be an excellent candidate. Herein, for the first time, we describe how an arginine-rich humanized antimicrobial cyclopeptide, θ-defensin, can be used as a synthetic cationic vector to load and deliver miRNA into bone mesenchymal stem cells with high efficiency and ultralow cytotoxicity, surpassing the efficiency of the commercial polyethylenimine (25 kD) and Lipofectamine 3000. To note, θ-defensin can redox-responsively release the loaded miRNA through a structural change: in extracellular oxidative environment, θ-defensin has large β-sheet structures stabilized by three disulfide linkages, and this special structure enables highly efficient delivery of miRNA by passing through cell membranes; in intracellular environment, redoxresponsive disulfide linkages are broken and the tight β-sheet structures are destroyed, so that the miRNA can be released. Our results suggest that synthetic θ-defensin peptides are a new class of nonviral gene vectors and this study may also provide a promising strategy to design smart-responsive gene vectors with high efficiency and minimal toxicity. miRNA Delivery

Small, 2019

Developing injectable nanocomposite conductive hydrogel dressings with multifunctions including a... more Developing injectable nanocomposite conductive hydrogel dressings with multifunctions including adhesiveness, antibacterial, and radical scavenging ability and good mechanical property to enhance full‐thickness skin wound regeneration is highly desirable in clinical application. Herein, a series of adhesive hemostatic antioxidant conductive photothermal antibacterial hydrogels based on hyaluronic acid‐graft‐dopamine and reduced graphene oxide (rGO) using a H2O2/HPR (horseradish peroxidase) system are prepared for wound dressing. These hydrogels exhibit high swelling, degradability, tunable rheological property, and similar or superior mechanical properties to human skin. The polydopamine endowed antioxidant activity, tissue adhesiveness and hemostatic ability, self‐healing ability, conductivity, and NIR irradiation enhanced in vivo antibacterial behavior of the hydrogels are investigated. Moreover, drug release and zone of inhibition tests confirm sustained drug release capacity of ...

Nanoscale, 2018

Most of the diseases such as tumors are usually accompanied by microbial infection especially aft... more Most of the diseases such as tumors are usually accompanied by microbial infection especially after surgical operation, which prevents successful cancer therapy.

Acta biomaterialia, Dec 15, 2016

Development of flexible degradable electroactive shape memory polymers (ESMPs) with tunable switc... more Development of flexible degradable electroactive shape memory polymers (ESMPs) with tunable switching temperature (around body temperature) for tissue engineering is still a challenge. Here we designed and synthesized a series of shape memory copolymers with electroactivity, super stretchability and tunable recovery temperature based on poly(ε-caprolactone) (PCL) with different molecular weight and conductive amino capped aniline trimer, and demonstrated their potential to enhance myogenic differentiation from C2C12 myoblast cells. We characterized the copolymers by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance ((1)H NMR), cyclic voltammetry (CV), ultraviolet-visible spectroscopy (UV-vis), differential scanning calorimetry (DSC), shape memory test, tensile test and in vitro enzymatic degradation study. The electroactive biodegradable shape memory copolymers showed great elasticity, tunable recovery temperature around 37°C, and good shape memory p...