. 2021 May 20;9(5):583. doi: 10.3390/biomedicines9050583

Table 1.

Cell-penetrating peptides used for nucleic acid transfection through peptide-based nanoparticle (PBN) formation.

Name	Sequence	Cargo	Ratio	Size (nm)	PdI	ZF (mV)	In Vitro Activity		In Vivo Activity	Ref
Name	Sequence	Cargo	Ratio	Size (nm)	PdI	ZF (mV)	Cells	Effect	In Vivo Activity	Ref
Poly-Cationic Familly
StA-R8	Stearyl-RRRRRRRR	siRNA	CR—4:1	185.2	n.d.	15.6	HepG2, A549	60% survivin KD	n.d.	[31]
OA-R8	Oleyl-RRRRRRRR	siRNA	CR—4:1	191.9		13.2	HepG2, A549	60% survivin KD	n.d.	[31]
K9[Ca²⁺]	KKKKKKKKK	pDNA	N/P—10	200–400	n.d.	~ +20 (1 mM KCl)	HeLa, A549, HEK-293, LLC, MDA-MB-231	Higher pLuc expression as PEI	Mice lung tumor	[32]
R9[Ca2+]	RRRRRRRRR	pDNA	N/P—10	200	n.d.	~ +20 (1 mM KCl)	A549, HEK-293	Higher or equal pLuc expression as PEI	n.d.	[33]
RH9[Ca2+]	RRHHRRHRR					~ +12 (1 mM KCl)
RA9[Ca2+]	RRAARRARR					~ +8 (1 mM KCl)
RL9[Ca2+]	RRLLRRLRR					~ +8 (1 mM KCl)
RW9[Ca2+]	RRWWRRWRR					~ +10 (1 mM KCl)
GALA/KALA/RALA familly
RALA	WEARLARALARALARHLARALARALRACEA-C	pDNA	N/P—10	51	0.35	+29 #	ZR-75-1, PC-3, NCTC-929	eGFP expression not better than Lipofectamin but less toxic	pLuc expression in the lungs and liver of mice	[34]
		siRNA	N/P—10	∼55–65	<0,60	∼ +20–25 #	ZR-75-1	Equal FKBPL KD compared to Oligofectamin but less toxic	RALA:siFKBPL has no effect on tumor growth	[35]
		siRNA	N/P—6	76.6	n.d.	+16.5 #	HMEC-1	Efficient FKBPL KD	RALA:siFKBPL in wound patches increases wound healing in mice	[36]
		siRNA	N/P—9	100–110	<0.35	~ +38 #	hDF (2D and 3D), THP-1 derived macrophages	Efficient MMP-9 KD	n.d.	[37]
		mRNA	N/P—10	91	n.d.	+26.3 #	DC2.4	Expression of eGFP	Increased T cell response compared to DOTAP transfection	[38]
RGSG	WEGRSGRGSGRGSGRHSGRGSGRGSRG-C	mRNA	N/P—10	150	n.d.	+2 #	DC2.4	No eGFP expression compared to RALA	Less T cell response compared to RALA	[38]
RRRR	WEGRRRRRRR-C	mRNA	N/P—10	1050	n.d.	−5 #	DC2.4	No eGFP expression compared to RALA	Less T cell response compared to RALA	[38]
PepFect/NickFect familly
PF14	Stearyl- AGYLLGKLLOOLAAAALOOLL	SCO	MR—5:1	363	n.d.	−28.4 (0.01 mM KCl)	HeLa pLuc705, U2OS, mdx mouse myotubes	Equal or better splice correction compared to Lipofectamin	n.d.	[39]
		mRNA	N/P—3	92	0.248–0.259	n.d.	SKOV-3 (2D and 3D)	eGFP expression Lower in 2D but higher in 3D compared to Lipofectamine MessengerMax	mCherry expression in xenografted mice	[40]
		SCO	MR—5:1	295.3 *	0.732 *	n.d.	HeLa pLuc 705	Internalization in comparison with small molecules	n.d.	[41]
PF14	Stearyl- AGYLLGKLLOOLAAAALOOLL	pDNA	N/P—2	~150	n.d.	~ +35 #	CHO	Dose-dependent pLuc expression	pLuc expression in the lungs and liver of mice	[42]
PF14-O	Stearyl-AGYLLGKLLOOLAOOALOOLL	pDNA	N/P—2	125	n.d.	~ +32 #	CHO	pLuc expression with PF14-O better than PF14-E	pLuc expression in the lungs and liver of mice
PF14-E	Stearyl-AGYLLGKLLEOLAAAALOOLL			125	n.d.	~ +35 #		pLuc expression with PF14-O better than PF14-E	n.d.
C0-PF14	AGYLLGKLLOOLAAAALOOLL			1500	n.d.	~ +8 #		Nearly no pLuc expression	n.d.
C10-PF14	Decanoyl-AGYLLGKLLOOLAAAALOOLL			100	n.d.	~ + 22 #		pLuc transfection with C10-PF14 lower than C22-PF14	n.d.
C22-PF14	Docosanoyl-AGYLLGKLLOOLAAAALOOLL			125	n.d.	~ +40 #		pLuc transfection with C10-PF14 lower than C22-PF14	pLuc expression in the lungs and liver of mice
C22-PF14-O	Docosanoyl-AGYLLGKLLOOLAOOALOOLL			100	n.d.	~ +30 #		pLuc transfection of C22-PF14 and C22-PF14-O equivalent to PF14 and better that C10-PF14	pLuc expression in the lungs and liver of mice
NF53	(Stearyl-AGYLLG)ε-KINLKALAALAKKIL	pDNA	CR—3:1	74.3	0.360	−14.9 (OptiMEM + 10% FBS)	CHO	Equal eGFP expression compared to LF200	n.d.	[43]
		SCO	MR—10:1	135.3	0.459	−8.8 (OptiMEM + 10% FBS)	HeLa pLuc 705	Lower splice correction compared to LF200
		siRNA	MR—10:1	68.6	0.529	−11.9 (OptiMEM + 10% FBS)	EGFP-CHO	Higher eGFP silencing compared to RNAiMax
NF61	Stearyl-AGYLLGKINLKALAALAKKIL	pDNA	CR—3:1	68.7	0.200	−17.9 (OptiMEM + 10% FBS)	CHO	Equal eGFP expression compared to LF200
		SCO	MR—10:1	60.5	0.286	−10.2 (OptiMEM + 10% FBS)	HeLa pLuc 705	Lower splice correction compared to LF200
		siRNA	MR—10:1	159.4	0.348	−13.6 (OptiMEM + 10% FBS)	EGFP-CHO	Equal eGFP silencing compared to RNAiMax
NF51	(Stearyl-AGYLLG)δ-OINLKALAALAKKIL	pDNA	CR—3:1	62	0.138	−11.5 (OptiMEM + 10% FBS)	CHO, MEF, Jurkat, A20	Higher eGFP expression compared to LF200
		SCO	MR—10:1	86.0	0.298	−11.1 (OptiMEM + 10% FBS)	HeLa pLuc 705	Higher splice correction compared to LF200
		siRNA	MR—10:1	74.2	0.197	−11.8 (OptiMEM + 10% FBS)	EGFP-CHO	Higher eGFP silencing compared to RNAiMax
NF51	(Stearyl-AGYLLG)δ-OINLKALAALAKKIL	pDNA	CR—4:1	n.d.	n.d.	n.d.	HeLa, U87-MG, N2A and HT1080	eGFP expression comparable to LF200, NF55 better than NF51 and NF54	pLuc expression in the lung, liver, and brain of healthy mice and those bearing intracranial tumors	[44]
NF54	(Stearyl-AGYLLG)δ-OINLKALAALAAKIL			n.d.
NF55	(Stearyl-AGYLLG)δ-OINLKALAALAKAIL			50–150
NF55	(Stearyl-AGYLLG)δ-OINLKALAALAKAIL	pDNA	CR—4:1	85 #	0.211	n.d.	CHO	pLuc expression comparable to Freiman 2016	pLuc lung expression	[45]
CADY-K/RICK family
CADY-K	GLWRALWRLLRSLWRLLWK	siRNA	MR—20:1	116	0.30	+38.0 (5 mM NaCl)	U87, Neuro2A, B16	Efficient Luciferase and CyclinB1 proteins KD	n.d.	[25,28]
d-Cady-k	glwralwrllrslwrllwk	siRNA	MR—20:1	90	0.30	+40.0 (5 mM NaCl)	U87 #
RICK	kwllrwlsrllrwlarwlg	siRNA	MR—20:1	92	0.24	+40.0 (5 mM NaCl)	U87 #
PEG-RICK	PEG₂₀₀₀-Ckwllrwlsrllrwlarwlg	siRNA	MR—20:1	69 (20% PEG)	0.29 (20% PEG)	+37.0 (20% PEG) (5 mM NaCl)	U87	Efficient Luciferase and CDK4 proteins KD for 20% PEG-RICK NPs and less cytotixicity than RNAimax.	20% PEG-RICK NPs significantly reduce liver and kidney accumulation in mice	[46]
WRAP family
WRAP1	LLWRLWRLLWRLWRLL	siRNA	MR—20:1	73.3	0.38	+42.2 (5 mM NaCl)	U87, KB, MCF7, HuH7, Neuro2A, MDA-MB-231, CMT93, HT29, RM1, GL261	Efficient Luciferase or CDK4 KD, fast internalization and less toxic than RNAimax	n.d.	[26]
WRAP5	LLRLLRWWWRLLRLL	siRNA	MR—20:1	80.0	0.29	+28.8 (5 mM NaCl)			n.d.	[26]
WRAP5	LLRLLRWWWRLLRLL	pDNA	N/P—3	102	n.d.	+33 (Tris buffer pH 7)	n.d.	n.d.	n.d.	[47]
C6 family
C6	RLLRLLLRLWRRLLRLLR	siRNA	MR—40:1	150–250	n.d.	+60.0 #	CHO-K1	Internalization of fluorescently labelled siRNA without cytotoxicity	n.d.	[48]
C6M1	RLWRLLWRLWRRLWRLLR	siRNA	MR—30:1	~70	n.d.	+31 (HEPES) +5 (PBS)	CHO-K1	Better internalization of fluorescently labelled siRNA than C6, significant inhibition of GAPDH expression	n.d.	[49,50]
C6M1	RLWRLLWRLWRRLWRLLR	siRNA	MR—60:1	~100–200	n.d.	~ +50 #	CHO-K1	Significant inhibition of GAPDH expression	Inhibition of tumor growth with Bcl-2 siRNA in A549 cancer cells xenografted in mice	[51]
C6M3	RLWHLLWRLWRRLHRLLR	siRNA	MR—40:1	~90	n.d.	+32.0 #	CHO-K1, RAW 264.7	Strong uptake CHO-K1 cells, significant inhibition of GAPDH expression and no significant cytokine induction	Inhibition of tumor growth with Bcl-2 siRNA in A549 cancer cells xenografted in mice	[52]
C6M6	GLWHLLLHLWRRLLRLLR	siRNA	MR—60:1	~110	n.d.	+36.0 #	CHO-K1, RAW 264.7			[52]
DM1	DEG-RLWRLLWRLWRRLWRLLR	siRNA	MR—40:1	n.d.	n.d.	n.d.	CHO-K1, C166-GFP	Significant inhibition of GAPDH and eGFP expression and DEGylation improves serum resistance	n.d.	[53]
Mpge family
Mgpe-1	SRLSHLRHHYSKKWHRFR	pDNA	N/P—10	80.13	0.151	+36.5 #	CHO-K1, MCF-7, A549	Equal pLuc expression as Lipofectamine but less toxic and higher pLuc expression than Cellfectin/Superfect	n.d.	[21]
Mgpe-2	LLYWFSRSHRHHSKKHRR		N/P—10	110.25	0.141	+31.95 #
Mgpe-3	RRLRHLRHHYRRRWHRFR		N/P—10	63.26	0.152	+33.5 #
Mgpe-4	LLYWFRRRHRHHRRRHRR		N/P—5	62.84	0.155	+25.45 #
Mgpe-10	CLLYWFRRRHRHHRRRHRRC	pDNA	N/P—10	128.49	0.166	+27.7 #	CHO-K1, MCF-7, A549, B16, B35, H 1299, HEK, Jurkat, MDA-MB-231, RAW, U87, T47D, Hela	Higher transfection efficiency, less toxic than Lipofectamine and Chondroitin sulfate combination	n.d.	[23,54]
Mgpe-9	CRRLRHLRHHYRRRWHRFRC	pDNA	N/P—10	85.77	0.240	+35.5 #			n.d.	[23,54]
		pDNA	N/P—10	50.63	n.d.	+24.0 #	dividing/differentiated ARPE-19/hfRPE cells	eGFP and Gaussia Luciferase expression	n.d.	[55]
		siRNA	N/P—10	173.9	n.d.	n.d.	Differentiated ARPE-19	80% GAPDH knockdown GAPDH for polyplexes at N/P 30 and combined with condroitin sulphate	n.d.	[55]
Other PBN-forming peptides
CHAT	CHHHRRRWRRRHHHC	pDNA	N/P—12	207	0.25	+29 #	MCF7, MDA-MB-231, DU-145, PC-3	eGFP expression comparable to RALA	10-fold increased pLuc expression in lung, liver and kidneys, 5-fold in tumor	[56]
StA-TH	Stearyl- AGYLLGHINLHHLAHL (Aib)HHIL	pDNA	N/P—3	>200 (TEM)	n.d.	n.d.	CHO, U251	High internalization and p53 activity (pro-apoptotic) at pH 5.5	n.d.	[57]
T9(dR)	GWTLNSAGYLLGKINLKALAALAKKIL-(dR)9	siRNA	MR 4:1	350–550	n.d.	n.d.	293T, MDCK, RAW, A549	Silencing of nucleoprotein expression	Better survival and weight recovery of PR8 influenza viru-infected mice	[58]
p5RHH	VLTTGLPALISWIRRRHRRHC	siRNA	MR—100:1	~55 (TEM)	n.d.	n.d.	/	/	Silencing NF-kB expression reduced chondrocyte apoptosi in a murine model of controlled knee joint impact injury	[59]
				~55 (TEM)	n.d.	~ +12 #	HUVEC	p65 slencing	n.d.	[60]
				n.d.	n.d.	n.d.	ARK1, OVCAR8	AXL silencing	Reduced tumor nodules and weight	[61]
		mRNA	350 ng mRNA:2.0 nmol p5RHH	<200	n.d.	+6 (OptiMEM)	B16F10, CASMC, HAoEC	RFP, Luc, GFP expression	RFP expression on injured femoral artery. mRNA construct (p27-miRNA-126-3p) prevents restenosis in a femoral artery wire injury mouse model	[62]
BR2	RAGLPFQVGRLLRRLLR	siRNA	N/P—8	150–200	n.d.	~ +10 #	HeLa, HCT116, HaCat, NIH3T3	GFP nd VEGF silencing comparable to PEI	n.d.	[63]
C18-S4₁₃-PV	Stearoyl-ALWKTLLKKVLKAPKKKRKVC	siRNA	CR—2	~250	n.d.	~+12 (HBS-2)	U87	No significant GFP silencing	n.d.	[64]
C16-S4₁₃-PV	Palmitoyl-ALWKTLLKKVLKAPKKKRKVC			~250		~+10 (HBS-2)		No significant GFP silencing
C14-S4₁₃-PV	Myristoyl-ALWKTLLKKVLKAPKKKRKVC			350		~ +10 (HBS-2)		GFP silencing
C12-S4₁₃-PV	Lauroyl-ALWKTLLKKVLKAPKKKRKVC			750		+8 (HBS-2)		GFP silencing
C12-S4₁₃-PV	Lauroyl-ALWKTLLKKVLKAPKKKRKVC	siRNA	CR—5	192	0.44	+23.6 (HBS)	U87, HeLa	GFP silencing lower than LF2000	n.d.	[65]
C12-H₅-S4₁₃-PV	Lauroyl-HHHHH-ALWKTLLKKVLKAPKKKRKVC			173	0.24	+22.6 (HBS)		GFP silencing equal to FL2000
H₅-S4₁₃-PV-C12	HHHHH-ALWKTLLKKVLKAPKKKRKVC-Lauroyl			184	0.69	+19.7 (HBS)		GFP silencing equal to FL2000
StA-SPA	Stearyl-rPKPwQwFwLL	pDNA	N/P—2	>200 (TEM)	n.d.	n.d.	CHO	Nearly equal pLuc expression as LF2000	n.d.	[66]
KL4	KLLLLKLLLLKLLLLKLLLLK	siRNA	(w/w)—20:1	280	0.28	n.d.	A549, BEAS-2B	Reduced GAPDH expression comparable to Lipofectamin 2000	n.d.	[67]

Footnotes: * values measured in serum-containing medium, # zeta potential measured in H₂O, n.d. = not determined.