An in vitro and in vivo study on the properties of hollow polycaprolactone cell-delivery particles

Abstract

The field of dermal fillers is evolving rapidly and numerous products are currently on the market. Biodegradable polymers such as polycaprolactone (PCL) have been found to be compatible with several body tissues, and this makes them an ideal material for dermal filling purposes. Hollow PCL spheres were developed by the Council for Scientific and Industrial Research (CSIR) to serve both as an anchor point and a “tissue harbour” for cells. Particles were tested for cytotoxicity and cell adherence using mouse embryo fibroblasts (MEF). MEFs adhered to the particles and no significant toxic effects were observed based on morphology, cell growth, cell viability and cell cycle analysis, suggesting that the particles are suitable candidates for cell delivery systems in an in vivo setting. The objective of providing a “tissue harbour” was however not realized, as cells did not preferentially migrate into the ported particles. In vivo studies were conducted in BALB/c mice into whom particles were introduced at the level of the hypodermis. Mice injected with PCL particles (ported and non-ported; with or without MEFs) showed evidence of local inflammation and increased adipogenesis at the site of injection, as well as a systemic inflammatory response. These effects were also observed in mice that received apparently inert (polystyrene) particles. Ported PCL particles can therefore act as a cell delivery system and through their ability to induce adipogenesis, may also serve as a dermal bulking agent.

Toxicity and Safety Study of D-PLEX100 in a Sternal Surgical Defect in New Zealand White Rabbits

“…Surgical site infections (SSIs) are infections that involve the site of the surgical procedure and all the additional tissues that are involved in the surgery (ter Boo et al 2015). They can be divided into superficial or deep incisional, or organ or deep-space infections (Pham et al 2016).…”

“…The rate of SSIs and the incidence in which multidrug resistant pathogens are involved continue to increase, resulting in a major threat to the economy and the public health (Badia et al 2017). In addition, SSIs result in a steep increase in morbidity and mortality following surgery (Kirkland et al 1999) and can lead to delayed wound healing (ter Boo et al 2015). Sternal wound infection is an example of an SSI with devastating complications, resulting in a 10.7% increase in 1-year mortality rate, longer hospitalization time, and higher costs (Sears et al 2016).…”

“…One of the key measures to prevent SSIs is perioperative administration of intravenous antimicrobial agents (Mangram et al 1999). However, the ability of this approach to prevent SSI is compromised by damage during surgery to local vasculature resulting in insufficient local antibiotic concentrations (ter Boo et al 2015). Increasing the dose of the administered antibiotics is not an appropriate approach due to systemic toxicity problems (ter Boo et al 2015).…”

“…However, the ability of this approach to prevent SSI is compromised by damage during surgery to local vasculature resulting in insufficient local antibiotic concentrations (ter Boo et al 2015). Increasing the dose of the administered antibiotics is not an appropriate approach due to systemic toxicity problems (ter Boo et al 2015). Other factors that affect the efficacy of preventive perioperative systemic antibiotic administration include the formation of biofilms in the wound bed by the pathogens and the increasing rate of antibiotic resistance (Bayramov and Neff 2017;Harbarth and Samore 2005;May et al 1998).…”

Safety and efficacy of polycaprolactone copolymer nanosphere hydrogel injected into the scalp dermal tissue of rats

“…At this particle size, the microspheres or particulates avoid being phagocytosed by macrophages, enabling them to exert a persistent effect [11]. However, this particle size can induce many side effects, including interruption of blood flow and formation of nodules in the surrounding tissues, due to vascular obstruction or mass effects [12,13]. The size also makes it difficult to inject fillers into the dermal layer of a dense tissue.…”