Abstract　Polymeric　micelles　are　one　important　class　of　nanoparticles　for　anticancer　drug　delivery,　but　the　impact　of　hydrophobic　segments　on　drug　encapsulation　and　release　is　unclear,　which　deters　the　rationalization　of　drug　encapsulation　into　polymeric　micelles.　This　paper　focused　on　studying　the　correlation　between　the　characteristics　of　hydrophobic　segments　and　encapsulation　of　structurally　different　drugs　(DOX　and　β-carotene).　Poly(ε-caprolactone)　(PCL)　or　poly(l-lactide)　(PLLA)　were　used　as　hydrophobic　segments　to　synthesize　micelle-forming　amphiphilic　block　copolymers　with　the　hydrophilic　methoxy-poly(ethylene　glycol)　(mPEG).　Both　blank　and　drug　loaded　micelles　were　spherical　in　shape　with　sizes　lower　than　50　nm.　PCL-based　micelles　exhibited　higher　drug　loading　capacity　than　their　PLLA-based　counterparts.　Higher　encapsulation　efficiency　of　β-carotene　was　achieved　compared　with　DOX.　In　addition,　both　doxorubicin　and　β-carotene　were　released　much　faster　from　PCL-based　polymeric　micelles.　Dissipative　particle　dynamics　(DPD)　simulation　revealed　that　the　two　drugs　tended　to　aggregate　in　the　core　of　the　PCL-based　micelles　but　disperse　in　the　core　of　PLLA　based　micelles.　In　vitro　cytotoxicity　investigation　of　DOX　loaded　micelles　demonstrated　that　a　faster　drug　release　warranted　a　more　efficient　cancer-killing　effect.　This　research　could　serve　as　a　guideline　for　the　rational　design　of　polymeric　micelles　for　drug　delivery.　©　2015　Elsevier　B.V.